Mention OP_RETURN as alternative

bip-PC.md

@@ -134,6 +134,10 @@ that get verified with `OP_CHECKSIGFROMSTACK` as a valid state update.
 `OP_PAIRCOMMIT` solves this specific problem without introducing a wide range
 of potentially controversial new behaviors, such as novel 2-way peg mechanisms.
 
+`OP_RETURN` could also be used for ensuring the availability of the state
+recovery data as `OP_CHECKTEMPLATEVERIFY` naturally commits to all outputs.
+However the weight unit cost of that would be over 4 times higher.
+
 ### Behaviours LNhance tries to avoid introducing
 
 The following behaviors are out of scope for LNhance and should not be enabled