Either A: have only items corresponding to the current Mayhem level drop so you know what level they’re going to be
Or B: if you make it so that all previous levels of a weapon can also drop, create a simple mayhem indicator for each weapon. This would be a huge quality of life improvement.
There’s too much time comparing newly dropped weapons to the insane amount already in the bank. (Which is compounded by the fact that there’s no “search” function for the bank either…)