If RSK’s recovery txs should be mined then they should be isstandard(). Why aren’t they already?
Off-chain tx acceleration is worth consideration. Braidpool could mine such txs into its deterministic mempool and prioritize them if we can figure out how to make an out of band fee go to the pool. (A competing pool could just steal the extra fee if an apparently-unrelated tx pays high fees) But frankly this should be handled by fee-bumping mechanisms in Bitcoin itself. Paying out-of-band for mining is a bug, not a feature. You should be able to bump fees.
I agree on the divergence from P2P relay policy generally…