Add rationale

KIPs/kip-247.md

@@ -157,6 +157,9 @@ This KIP implements `TxBundlingModule` specified in [KIP-245](https://kips.kaia.
 
 ```
 ExtractTxBundles(txs, prevBundles):
+    if GaslessTx is disabled:
+        return nothing
+
     filter ApproveTx, SwapTx from txs
     move ApproveTx (if exists) before SwapTx
     inject LendTx before ApproveTx if exists, otherwise before SwapTx
@@ -166,7 +169,9 @@ ExtractTxBundles(txs, prevBundles):
 
 ### Disabling GaslessTx
 
-If many validators disabled GaslessTx, how does this affect UX?
+If many consensus nodes disabled GaslessTx feature, users may experience increased transaction latency.
+However, as long as there are still nodes supporting GaslessTx, the transactions will eventually be executed.
+Also, because this feature is enabled by default, few consensus nodes are expected to disable it.
 
 ## Backward Compatibility