Important reminder, Quantum attacks remain purely theoretical— the existing quantum “computers” could not break your security if you gave them your seed phrase and private keys.
They can’t even do the forward elliptical curve calculation, let alone reverse.
Defending against theoretic attacks should remain purely theoretical. You can’t make a meaningful BIP without specific details of what a future quantum computer would do. It’s like trying to defend against laser guided missiles in the Stone Age.
Despite all the hype, we’re closer to cold fusion and Alcubierre warp drives than we are to stable qbits sufficient to attack weak versions of RSA, let alone Bitcoin’s elliptical curve.