Can't get glowforge to stop burning design

Ok, Baltic birch has definitely been used successfully so you should be able to use it. The problem of course is there are many grades of BB - some ab fab, some not so much.

I’d suggest holding a bright light to the back of your wood to verify if there are any voids/fills in it (they’ll look like black spots) - you’ll need to avoid those.

Then start with this test pattern: