Maybe a setting like in Smash Ultimate where if you hold the B button you are prevented from rolling or spotdodging while in shield, obviously doesnt have all of the same applications as shield shifting is not in this game, but it would help with wavedashing out of shield in order to prevent accidental rolls.

This would be a great feature, but B while shielding is bound to parry currently. What might work better is an alternate shield input that couldn’t be rolled or spotdodged out of, since most players have 2 shield buttons bound.
I don’t know which other buttons do this but if you have a walk modifier button bound, you can hold that while shielding and it will lock your shield.