I've kind of avoided doing this, but here we go, two specific changes that I think would make the system better.
1) D2's do not trade with Air attacks. When you hit someone with a d2, and they are in the air, the anti-air outprioritizes the air. Clean 14%. No trades.
2) Universal active-frame buff to D2's. Not startup, not more + on block, just more active frames. If the hitbox lingers out there a bit longer (even 2 extra frames would help) it will result in alot less stuffed D2's that are otherwise perfectly done.