Welcome to the forum @LeCryptoMath Excited to see this proposal being discussed here. I hope this proposal will be accepted very soon.
Some comments regarding the fee mechanism:
The current default fee is not currently enforced by the protocol. It is conventional and were only intended as social consensus between “wallet developers, miners & Zcash users”. A transaction can still be valid even if they don’t follow ZIP-313. If ZSA were to be added with this mechanism, are you guys proposing the fee to be enforced or “as-is” (i.e. enforced socially but not at protocol-level)?