well if you had a moisture meter and you checked the bow before and after,, it would probably be a lower moisture content,, maybe not enough to break the bow,,,, but there is probably some moisture loss,,, and that could enhance performance as well ,,, and may be part of what the toasting does that is desirable in some instances,,,, when you put a hickory bow in the heat box and get the moisture way down,, it doesnt break,, just resist set and shoots better,,,
,,,, some woods may explode
I dont toast enough to have experience with the exploding woods,,,