On Wednesday, November 17th, 2021 at 1:07 PM, Andrew Chow via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:

Prior to 0.19.0, creating outputs with an unknown witness version was considered non-standard. This was a violation of BIP 173 and was fixed for 0.19.0+ in PR #15846.

That's correct, but I think OP's problem is with getting P2TR _spends_ to relay. Those will be rejected by all post-segwit pre-taproot Bitcoin Core releases, as far as I know.

Pieter