I don't really need Taproot, or any other things that add complexity in the code. Im even ok with legacy only, since I rarely make transactions,
and anything after legacy for me adds a tradeoff in security no way how you want to put it-snip-
Since you've written that no one can change your mind:
Use Bitcoin Core v0.20.2 which doesn't include TapRoot implementations (
including test networks), but its last patch was 3 years ago so use it at your own risk.
That client wont relay transactions that has TapRoot inputs but will still accept the blockchain like a normal Bitcoin node would.
And its GUI/RPC supports PSBT, but quite outdated.