Depends on what "work" means. Not having random unencrypted data in my mempool is already working. Not relaying that data is already working. If it's returned to me in a confirmed state by miners, then the responsibility of that confirmation lies with them. Law enforcement / society will target the...

The easiest choise is Core 29, if you're not onboard with knots, and don't have a use case for a larger op return. Since I understand datacarriersize is essentially depricated now.

Different implementations are non-partisan and perfectly fine as long as consensus rules match. Like you said, Knots is basically Core with extra relay options, and for Core/Knots team to deviate into hard-fork territory would be an insane move, and bad for Lightning. The good thing about Bitcoin ...