I buy and starch pre-cuts (except for the tiny ones).
Shrinkage is not a problem. If it's a layer cake I just plan for a 9.5" square.
If it's a charm pack, I plan for 4.5" square. I usually cut them into smaller
pieces anyway. When you buy a FQ or yardage, you still have to trim.
So, what's different with pre-cuts?