-snip-
This is like saying we need to go back prior to core 24 and prior to implementing full-rbf.
What you are suggesting is to flag a transaction as full-rbf or not-rbf which doesn't make much sense. Please enlighten me if I'm getting this wrong. Afaik, it's all about the consensus, not about your nodes settings.
Since we're in Electrum board, his suggestion to utilize
nSequence field is equivalent to disabling replace-by-fee setting in older Electrum versions.
Opt-in RBF is still being enforced by nodes that didn't enabled "
mempoolfullrbf" settings.
So it makes sense but not different from the original concern of opting-out from opt-in rbf being less effective.