Possible vaulting solution

We all know the 2-3 star transition is terribly long and that vaulting only extends this. What if albeit rarely the vaulted three stars dropped from PVP battles? I have played this game for roughly 250 days and am almost done the transition. But having 1-2 of the vaulted characters every season instead of my 1000,1001 cover of purple moonstone would help immensely.

Thoughts?

Solution for having “to many characters, we have to vault some” - raise heroic drop rates to about 10%. Leave 4*'s at a very low rate to make them feel special. This also solves the problem of heroic tokens not feeling very special.

Your chance of getting any specific character will remain low, but your chance of getting SOME character would grow. More will drop so folks will get a varied roster a little faster, and folks won’t mind the slight bump in ISO (also needed) for selling a 3* character they already have.

The game is shifting to 4* so the 2*->3* transition needs to become easier. Keep 4* rare and hard to get.