UDS build, concave bottom question

So, the drum has a pretty rounded out bottom, to the point where I was tempted to cut that end off instead, but the lid fits a lot better on top. so....

If I just shim up the bottom, would the thing flatten out when I do the burn?

This worked pretty well, btw, put 3 10" bricks in a triangle, so they didn't touch the rim. Had a small, hot burn with pruning junk, up to about 1.5" in diameter, and about 25m into the burn, it dropped down. Sits on the rim now on flat ground.

Just ICYGAS.