There is, potentially, a cool trick which could help though! Jeremy proposed a kind of "neighbor fee" tx which would pay the fees for the immediately-preceding tx in a block (which, annoyingly, I can't find now! Anyone?). You really want this to stack (so it's probably better as a forward, rather than backward bit) and I don't think there's any code, but it makes CTV a more obviously optimal choice for simple covenants, AFAICT.