diff --git a/.github/unittest/linux_examples/scripts/run_test.sh b/.github/unittest/linux_examples/scripts/run_test.sh
index bcc688b0a6d..075489b208d 100755
--- a/.github/unittest/linux_examples/scripts/run_test.sh
+++ b/.github/unittest/linux_examples/scripts/run_test.sh
@@ -86,8 +86,6 @@ python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/dd
   replay_buffer.size=120 \
   env.name=Pendulum-v1 \
   logger.backend=
-#  record_video=True \
-#  record_frames=4 \
 python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/a2c/a2c_mujoco.py \
   env.env_name=HalfCheetah-v4 \
   collector.total_frames=40 \
@@ -125,7 +123,7 @@ python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/re
   collector.env_per_collector=2 \
   buffer.batch_size=10 \
   optim.steps_per_batch=1 \
-  logger.record_video=True \
+  logger.video=True \
   logger.record_frames=4 \
   buffer.size=120 \
   logger.backend=
@@ -151,8 +149,6 @@ python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/di
   replay_buffer.size=120 \
   env.name=CartPole-v1 \
   logger.backend=
-#  logger.record_video=True \
-#  logger.record_frames=4 \
 python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/dreamer/dreamer.py \
   collector.total_frames=200 \
   collector.init_random_frames=10 \
@@ -220,8 +216,6 @@ python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/dd
   replay_buffer.size=120 \
   env.name=Pendulum-v1 \
   logger.backend=
-#  record_video=True \
-#  record_frames=4 \
 python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/dqn/dqn_atari.py \
   collector.total_frames=48 \
   collector.init_random_frames=10 \
@@ -238,7 +232,7 @@ python .github/unittest/helpers/coverage_run_parallel.py sota-implementations/re
   collector.env_per_collector=1 \
   buffer.batch_size=10 \
   optim.steps_per_batch=1 \
-  logger.record_video=True \
+  logger.video=True \
   logger.record_frames=4 \
   buffer.size=120 \
   logger.backend=
diff --git a/sota-implementations/redq/redq.py b/sota-implementations/redq/redq.py
index d6b1668aadf..c6b96db9292 100644
--- a/sota-implementations/redq/redq.py
+++ b/sota-implementations/redq/redq.py
@@ -76,7 +76,7 @@ def main(cfg: "DictConfig"):  # noqa: F821
             },
         )
     else:
-        logger = ""
+        logger = None
 
     key, init_env_steps, stats = None, None, None
     if not cfg.env.vecnorm and cfg.env.norm_stats:
@@ -174,14 +174,14 @@ def main(cfg: "DictConfig"):  # noqa: F821
             t.loc.fill_(0.0)
 
     trainer = make_trainer(
-        collector,
-        loss_module,
-        recorder,
-        target_net_updater,
-        actor_model_explore,
-        replay_buffer,
-        logger,
-        cfg,
+        collector=collector,
+        loss_module=loss_module,
+        recorder=recorder,
+        target_net_updater=target_net_updater,
+        policy_exploration=actor_model_explore,
+        replay_buffer=replay_buffer,
+        logger=logger,
+        cfg=cfg,
     )
 
     trainer.train()
diff --git a/test/test_env.py b/test/test_env.py
index f5f1f37ed8e..d0ccc2cff57 100644
--- a/test/test_env.py
+++ b/test/test_env.py
@@ -1832,7 +1832,16 @@ def test_info_dict_reader(self, device, seed=0):
             import gym
 
         env = GymWrapper(gym.make(HALFCHEETAH_VERSIONED()), device=device)
-        env.set_info_dict_reader(default_info_dict_reader(["x_position"]))
+        env.set_info_dict_reader(
+            default_info_dict_reader(
+                ["x_position"],
+                spec=CompositeSpec(
+                    x_position=UnboundedContinuousTensorSpec(
+                        dtype=torch.float64, shape=()
+                    )
+                ),
+            )
+        )
 
         assert "x_position" in env.observation_spec.keys()
         assert isinstance(
@@ -1842,15 +1851,21 @@ def test_info_dict_reader(self, device, seed=0):
         tensordict = env.reset()
         tensordict = env.rand_step(tensordict)
 
-        assert env.observation_spec["x_position"].is_in(
-            tensordict[("next", "x_position")]
+        x_position_data = tensordict["next", "x_position"]
+        assert env.observation_spec["x_position"].is_in(x_position_data), (
+            x_position_data.shape,
+            x_position_data.dtype,
+            env.observation_spec["x_position"],
         )
 
         for spec in (
-            {"x_position": UnboundedContinuousTensorSpec(10)},
-            None,
-            CompositeSpec(x_position=UnboundedContinuousTensorSpec(10), shape=[]),
-            [UnboundedContinuousTensorSpec(10)],
+            {"x_position": UnboundedContinuousTensorSpec((), dtype=torch.float64)},
+            # None,
+            CompositeSpec(
+                x_position=UnboundedContinuousTensorSpec((), dtype=torch.float64),
+                shape=[],
+            ),
+            [UnboundedContinuousTensorSpec((), dtype=torch.float64)],
         ):
             env2 = GymWrapper(gym.make("HalfCheetah-v4"))
             env2.set_info_dict_reader(
@@ -1859,9 +1874,12 @@ def test_info_dict_reader(self, device, seed=0):
 
             tensordict2 = env2.reset()
             tensordict2 = env2.rand_step(tensordict2)
-
-            assert env2.observation_spec["x_position"].is_in(
-                tensordict2[("next", "x_position")]
+            data = tensordict2[("next", "x_position")]
+            assert env2.observation_spec["x_position"].is_in(data), (
+                data.dtype,
+                data.device,
+                data.shape,
+                env2.observation_spec["x_position"],
             )
 
     @pytest.mark.skipif(not _has_gym, reason="no gym")
diff --git a/test/test_exploration.py b/test/test_exploration.py
index e6493bd1804..89de8005555 100644
--- a/test/test_exploration.py
+++ b/test/test_exploration.py
@@ -254,7 +254,11 @@ def test_ou_wrapper(self, device, d_obs=4, d_act=6, batch=32, n_steps=100, seed=
         out_noexp = []
         out = []
         for i in range(n_steps):
-            tensordict_noexp = policy(tensordict.clone())
+            tensordict_noexp = policy(
+                tensordict.clone().exclude(
+                    *(key for key in tensordict.keys() if key.startswith("_"))
+                )
+            )
             tensordict = exploratory_policy(tensordict.clone())
             if i == 0:
                 assert (tensordict[exploratory_policy.ou.steps_key] == 1).all()
diff --git a/test/test_tensordictmodules.py b/test/test_tensordictmodules.py
index 75ae396d95d..4527e32d16b 100644
--- a/test/test_tensordictmodules.py
+++ b/test/test_tensordictmodules.py
@@ -8,7 +8,7 @@
 import pytest
 import torch
 from mocking_classes import CountingEnv, DiscreteActionVecMockEnv
-from tensordict import pad, TensorDict, unravel_key_list
+from tensordict import LazyStackedTensorDict, pad, TensorDict, unravel_key_list
 from tensordict.nn import InteractionType, TensorDictModule, TensorDictSequential
 from torch import nn
 from torchrl.data.tensor_specs import (
@@ -515,7 +515,7 @@ def test_sequential_partial(self, stack):
         )
 
         if stack:
-            td = torch.stack(
+            td = LazyStackedTensorDict.maybe_dense_stack(
                 [
                     TensorDict({"a": torch.randn(3), "b": torch.randn(4)}, []),
                     TensorDict({"a": torch.randn(3), "c": torch.randn(4)}, []),
diff --git a/test/test_transforms.py b/test/test_transforms.py
index 36408bf4964..c9d2fb8c031 100644
--- a/test/test_transforms.py
+++ b/test/test_transforms.py
@@ -10583,6 +10583,7 @@ def test_multistep_transform(self):
 
         outs_2 = []
         td = env.reset().contiguous()
+        assert "reward" not in td
         for _ in range(1):
             rollout = env.rollout(
                 250, auto_reset=False, tensordict=td, break_when_any_done=False
@@ -10626,7 +10627,7 @@ def test_multistep_transform(self):
             ).contiguous()
             assert "reward" not in rollout.keys()
             out = t._inv_call(rollout)
-            td = rollout[..., -1]["next"]
+            td = rollout[..., -1]["next"].exclude("reward")
             if out is not None:
                 outs_3.append(out)
 
diff --git a/torchrl/data/replay_buffers/replay_buffers.py b/torchrl/data/replay_buffers/replay_buffers.py
index 8a4b3e517dd..f75eaaeedcf 100644
--- a/torchrl/data/replay_buffers/replay_buffers.py
+++ b/torchrl/data/replay_buffers/replay_buffers.py
@@ -39,6 +39,7 @@
 )
 from torchrl.data.replay_buffers.storages import (
     _get_default_collate,
+    _stack_anything,
     ListStorage,
     Storage,
     StorageEnsemble,
@@ -1541,8 +1542,10 @@ def __init__(
         num_buffer_sampled: int | None = None,
         **kwargs,
     ):
+
         if collate_fn is None:
-            collate_fn = torch.stack
+            collate_fn = _stack_anything
+
         if rbs:
             if storages is not None or samplers is not None or writers is not None:
                 raise RuntimeError
diff --git a/torchrl/data/replay_buffers/storages.py b/torchrl/data/replay_buffers/storages.py
index 7d4fb64babd..a1ada2eb72e 100644
--- a/torchrl/data/replay_buffers/storages.py
+++ b/torchrl/data/replay_buffers/storages.py
@@ -18,7 +18,12 @@
 import numpy as np
 import tensordict
 import torch
-from tensordict import is_tensor_collection, TensorDict, TensorDictBase
+from tensordict import (
+    is_tensor_collection,
+    LazyStackedTensorDict,
+    TensorDict,
+    TensorDictBase,
+)
 from tensordict.memmap import MemmapTensor, MemoryMappedTensor
 from tensordict.utils import _STRDTYPE2DTYPE
 from torch import multiprocessing as mp
@@ -1322,6 +1327,12 @@ def _collate_list_tensordict(x):
     return out
 
 
+def _stack_anything(x):
+    if is_tensor_collection(x[0]):
+        return LazyStackedTensorDict.maybe_dense_stack(x)
+    return torch.stack(x)
+
+
 def _collate_id(x):
     return x
 
diff --git a/torchrl/data/tensor_specs.py b/torchrl/data/tensor_specs.py
index c9d0683ad9c..105c13214e0 100644
--- a/torchrl/data/tensor_specs.py
+++ b/torchrl/data/tensor_specs.py
@@ -974,14 +974,18 @@ def zero(self, shape=None) -> TensorDictBase:
             dim = self.dim + len(shape)
         else:
             dim = self.dim
-        return torch.stack([spec.zero(shape) for spec in self._specs], dim)
+        return LazyStackedTensorDict.maybe_dense_stack(
+            [spec.zero(shape) for spec in self._specs], dim
+        )
 
     def rand(self, shape=None) -> TensorDictBase:
         if shape is not None:
             dim = self.dim + len(shape)
         else:
             dim = self.dim
-        return torch.stack([spec.rand(shape) for spec in self._specs], dim)
+        return LazyStackedTensorDict.maybe_dense_stack(
+            [spec.rand(shape) for spec in self._specs], dim
+        )
 
     def to(self, dest: Union[torch.dtype, DEVICE_TYPING]) -> T:
         if dest is None:
@@ -4344,7 +4348,7 @@ def project(self, val: TensorDictBase) -> TensorDictBase:
                 vals.append(spec.project(subval))
             else:
                 vals.append(subval)
-        res = torch.stack(vals, dim=self.dim)
+        res = LazyStackedTensorDict.maybe_dense_stack(vals, dim=self.dim)
         if not isinstance(val, LazyStackedTensorDict):
             res = res.to_tensordict()
         return res
diff --git a/torchrl/envs/gym_like.py b/torchrl/envs/gym_like.py
index 6c1dbbd0389..b27c1f795a2 100644
--- a/torchrl/envs/gym_like.py
+++ b/torchrl/envs/gym_like.py
@@ -6,6 +6,7 @@
 from __future__ import annotations
 
 import abc
+import re
 import warnings
 from typing import Any, Dict, List, Mapping, Optional, Sequence, Tuple, Union
 
@@ -506,13 +507,18 @@ def auto_register_info_dict(self):
         try:
             check_env_specs(self)
             return self
-        except AssertionError as err:
-            if "The keys of the specs and data do not match" in str(err):
-                result = TransformedEnv(
-                    self, TensorDictPrimer(self.info_dict_reader[0].info_spec)
-                )
-                check_env_specs(result)
-                return result
+        except (AssertionError, RuntimeError) as err:
+            patterns = [
+                "The keys of the specs and data do not match",
+                "The sets of keys in the tensordicts to stack are exclusive",
+            ]
+            for pattern in patterns:
+                if re.search(pattern, str(err)):
+                    result = TransformedEnv(
+                        self, TensorDictPrimer(self.info_dict_reader[0].info_spec)
+                    )
+                    check_env_specs(result)
+                    return result
             raise err
 
     def __repr__(self) -> str:
diff --git a/torchrl/envs/utils.py b/torchrl/envs/utils.py
index cd51b4fd23b..08615ea12ae 100644
--- a/torchrl/envs/utils.py
+++ b/torchrl/envs/utils.py
@@ -193,7 +193,6 @@ def _is_reset(key: NestedKey):
             expected = set(expected)
             self.validated = expected.intersection(actual) == expected
             if not self.validated:
-                raise RuntimeError
                 warnings.warn(
                     "The expected key set and actual key set differ. "
                     "This will work but with a slower throughput than "