Advice for first time annealer

I’ll be starting an Orca frame or a CZAR frame as my next project (still figuring out which I want to do). I want to try annealing with either PA6-CF or PET-CF. My biggest concern is so many people mention potential shrinkage. When I do the annealing, do I put all the FCG and metal parts in first so the shrinkage happens around the parts? I’m concerned with too much shrinkage either changing the dimensions so much I can’t fit the parts properly, or ruining the frame. Any advice from those of you that have already done this would be appreciated!