Brief overview of my current thoughts, for whatever they’re worth:
I’d be happy to modify BIP-119 to omit legacy script support for CTV if there’s a 34-byte “witness v2” along the lines of what @instagibbs sketched out.
My hold out here had been that I thought the BitVM “sibling input requirement” trick relies upon legacy use, but it does not. Note that I still think CTV availability in witness v0 is worth preserving for reasons mentioned above.
If there’s demand to introduce a push-style OP_TEMPLATEHASH that puts the CTV digest on the stack, that sounds like a totally reasonable and low-effort/risk enhancement to me.
Do the stakeholders opining here think there could be consensus around this? Namely:
- BIP-119 modified to remove legacy script support (but retaining wit v0 support),
- definition of a witness v2 per instagibb’s patch, and
- inclusion of a tapscript-only
OP_TEMPLATEHASH?