Yeah absolutely, as I said in a another branch of this thread, it's all just (plaintext even) 1s & 0s at the end of the day, you can flip some; I do understand that.
It's just that our starting point here was something like 'what can a software engineer do in an hour or so one evening to get their home DNS traffic going through a Raspberry Pi on the LAN'.
I happened to have, er, exactly this experience recently with my (OpenWRT) router(+...) and with that tooling, I couldn't make it work. I settled for DNAT for v4 & DROP^ for v6 because that's what I could get done that evening and it didn't (and hasn't) seem(ed) to be a problem.
^(as in, anything trying to use a different IP, if it's already destined for my DNS that's fine. The hope being that it falls back on v4 at least, even if not the provided DNS over v6.)