diff --git a/.github/workflows/mcstas-basictest.yml b/.github/workflows/mcstas-basictest.yml
index 54fb50d8c3..01a7801684 100644
--- a/.github/workflows/mcstas-basictest.yml
+++ b/.github/workflows/mcstas-basictest.yml
@@ -18,15 +18,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { os: ubuntu-20.04,  CC: gcc-10,   CXX: g++-10,     python: '3.8'  }
-          - { os: ubuntu-22.04,  CC: gcc,      CXX: g++,        python: '3.9'  }
-          - { os: ubuntu-22.04, CC: gcc,      CXX: g++,        python: '3.10' }
-          - { os: ubuntu-22.04, CC: clang,    CXX: clang++,    python: '3.11' }
-          - { os: ubuntu-22.04, CC: gcc-12,   CXX: g++-12,     python: '3.11' }
-          - { os: macos-13,      CC: clang,    CXX: clang++,    python: "3.11" }
-#         - { os: macos-14,      CC: clang,    CXX: clang++,    python: "3.11" }
-#         - { os: macos-15,      CC: clang,    CXX: clang++,    python: "3.11" }
-          - { os: windows-latest,  CC: gcc,    CXX: g++,        python: "3.11" }
+          - { os: ubuntu-24.04,  CC: gcc-13,   CXX: g++-13,     python: '3.12'  }
+          - { os: ubuntu-24.04,  CC: clang,    CXX: clang++,    python: '3.12'  }
+          - { os: ubuntu-22.04,  CC: clang,    CXX: clang++,    python: '3.11'  }
+          - { os: ubuntu-22.04,  CC: gcc-12,   CXX: g++-12,     python: '3.11'  }
+          - { os: macos-14,      CC: clang,    CXX: clang++,    python: "3.12"  }
+          - { os: macos-15,      CC: clang,    CXX: clang++,    python: "3.13"  }
+          - { os: windows-latest,  CC: gcc,    CXX: g++,        python: "3.12"  }
 
     name: ${{ matrix.os }}.${{ matrix.CC }}.python-${{ matrix.python }}
     runs-on: ${{ matrix.os }}
@@ -67,9 +65,9 @@ jobs:
       run: |
            sudo apt -y install libopenmpi-dev
 
-    - name: Setup OpenMPI (macOS-12,13)
+    - name: Setup OpenMPI (macOS)
       id: setup-openmpi-macos12
-      if: runner.os == 'macOS' && matrix.os != 'macos-11'
+      if: runner.os == 'macOS'
       run: |
            brew install openmpi
 
@@ -93,7 +91,7 @@ jobs:
            mkdir build_mcstas
            cd build_mcstas
            export EXTRA_ARGS_FOR_CMAKE=""
-           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/usr/local/opt/bison/bin/bison -DFLEX_EXECUTABLE=/usr/local/opt/flex/bin/flex"; fi
+           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/opt/homebrew/opt/bison/bin/bison -DFLEX_EXECUTABLE=/opt/homebrew/opt/flex/bin/flex"; fi
            if [ "$RUNNER_OS" == "Linux" ]; then export EXTRA_ARGS_FOR_CMAKE="-DNEXUSLIB=/usr/lib -DNEXUSINCLUDE=/usr/include/nexus"; fi
            cmake \
                -DCMAKE_INSTALL_PREFIX=../install_mcstas \
@@ -138,10 +136,17 @@ jobs:
            set -e
            set -u
            set -x
-           python3 -mpip install PyYAML ply McStasscript
-           if [ "$RUNNER_OS" != "Windows" ];
+           if [ "$RUNNER_OS" == "Windows" ];
+           then
+             python3 -mpip install PyYAML ply McStasscript
+           fi
+           if [ "$RUNNER_OS" == "macOS" ];
+           then
+             python3 -mpip install PyYAML ply McStasScript ncrystal --break-system-packages
+           fi
+           if [ "$RUNNER_OS" == "Linux" ];
            then
-             python3 -mpip install ncrystal
+             python3 -mpip install PyYAML ply McStasscript ncrystal
            fi
 
     - name: Launch BNL_H8 instrument
@@ -169,7 +174,7 @@ jobs:
 
     - name: Launch BNL_H8 instrument (MPI)
       id: h8-test-mpi
-      if: runner.os == 'Linux'  || (runner.os == 'macOS' && matrix.os != 'macos-11') # Linux or macos-12/13 only
+      if: runner.os == 'Linux'  || (runner.os == 'macOS' )
       run: |
            set -e
            set -u
@@ -202,7 +207,7 @@ jobs:
 
     - name: Launch MCPL test instrument (mpi)
       id: mcpl-test-mpi
-      if: runner.os == 'Linux'  || (runner.os == 'macOS' && matrix.os != 'macos-11') # Linux or macos-12/13 only
+      if: runner.os == 'Linux'  || runner.os == 'macOS' # Linux or macos only
       # Status: Works on Unixes ("wrapper batches missing for Windows")
       run: |
            set -e
@@ -236,7 +241,7 @@ jobs:
 
     - name: Launch NCrystal test instrument (mpi)
       id: ncrystal-test-mpi
-      if: runner.os == 'Linux' 
+      if: runner.os == 'Linux' || runner.os == 'macOS'  # Linux or macOS only
       # Status: Works on Unixes ("ncrystal missing for Windows")
       run: |
            set -e
@@ -253,7 +258,7 @@ jobs:
            mpirun --version
            ncrystal-config --version
            if [ "x$(uname)" == "xLinux" ]; then
-               export NUM_MPI=2
+           export NUM_MPI=2
            else
                export NUM_MPI=1
            fi
diff --git a/.github/workflows/mcxtrace-basictest.yml b/.github/workflows/mcxtrace-basictest.yml
index 670bf8fd17..5bb002f134 100644
--- a/.github/workflows/mcxtrace-basictest.yml
+++ b/.github/workflows/mcxtrace-basictest.yml
@@ -18,15 +18,13 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { os: ubuntu-20.04,  CC: gcc-10,   CXX: g++-10,     python: '3.8'  }
-          - { os: ubuntu-22.04,  CC: gcc,      CXX: g++,        python: '3.9'  }
-          - { os: ubuntu-22.04, CC: gcc,      CXX: g++,        python: '3.10' }
+          - { os: ubuntu-24.04,  CC: gcc-13,   CXX: g++-13,     python: '3.12'  }
+          - { os: ubuntu-24.04,  CC: clang,    CXX: clang++,    python: '3.12'  }
           - { os: ubuntu-22.04, CC: clang,    CXX: clang++,    python: '3.11' }
           - { os: ubuntu-22.04, CC: gcc-12,   CXX: g++-12,     python: '3.11' }
-          - { os: macos-13,      CC: clang,    CXX: clang++,    python: "3.11" }
-#         - { os: macos-14,      CC: clang,    CXX: clang++,    python: "3.11" }
-#         - { os: macos-15,      CC: clang,    CXX: clang++,    python: "3.11" }
-          - { os: windows-latest,  CC: gcc,    CXX: g++,        python: "3.11" }
+          - { os: macos-14,      CC: clang,    CXX: clang++,    python: "3.12"  }
+          - { os: macos-15,      CC: clang,    CXX: clang++,    python: "3.13"  }
+          - { os: windows-latest,  CC: gcc,    CXX: g++,        python: "3.12"  }
 
     name: ${{ matrix.os }}.${{ matrix.CC }}.python-${{ matrix.python }}
     runs-on: ${{ matrix.os }}
@@ -67,9 +65,9 @@ jobs:
       run: |
            sudo apt -y install libopenmpi-dev
 
-    - name: Setup OpenMPI (macOS-12,13)
+    - name: Setup OpenMPI (macOS)
       id: setup-openmpi-macos12
-      if: runner.os == 'macOS' && matrix.os != 'macos-11'
+      if: runner.os == 'macOS'
       run: |
            brew install openmpi
 
@@ -93,7 +91,9 @@ jobs:
            mkdir build_mcxtrace
            cd build_mcxtrace
            export EXTRA_ARGS_FOR_CMAKE=""
-           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/usr/local/opt/bison/bin/bison -DFLEX_EXECUTABLE=/usr/local/opt/flex/bin/flex"; fi
+           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/opt/homebrew/opt/bison/bin/bison -DFLEX_EXECUTABLE=/opt/homebrew/opt/flex/bin/flex"; fi
+           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/opt/homebrew/opt/bison/bin/bison -DFLEX_EXECUTABLE=/opt/homebrew/opt/flex/bin/flex"; fi
+           if [ "$RUNNER_OS" == "macOS" ]; then export EXTRA_ARGS_FOR_CMAKE="-DBISON_EXECUTABLE=/opt/homebrew/opt/bison/bin/bison -DFLEX_EXECUTABLE=/opt/homebrew/opt/flex/bin/flex"; fi
            if [ "$RUNNER_OS" == "Linux" ]; then export EXTRA_ARGS_FOR_CMAKE="-DNEXUSLIB=/usr/lib -DNEXUSINCLUDE=/usr/include/nexus"; fi
            cmake \
                -DCMAKE_INSTALL_PREFIX=../install_mcxtrace \
@@ -137,7 +137,15 @@ jobs:
            set -e
            set -u
            set -x
-           python3 -mpip install PyYAML ply McStasscript
+           if [ "$RUNNER_OS" != "macOS" ];
+           then
+            python3 -mpip install PyYAML ply McStasscript
+           fi
+           if [ "$RUNNER_OS" == "macOS" ];
+           then
+             python3 -mpip install PyYAML ply McStasScript --break-system-packages
+           fi
+
 
     - name: Launch JJ_SAXS instrument
       id: JJ_SAXS-basic