Crossovers are the same price as getting it graded and I’m pretty sure they will only crack the case if there is a grade change or you re-encapsulate it.
I would imagine if you’re paying them to do a full regrade they would crack the case to do it then put it in a new case. Looking at a card through a case doesn’t seem like a very professional way of grading to me. I’m not an expert on this by any means though.
*"No, if you send a card in for review graders grade your card while it’s still encapsulated and make a decision on whether the grade should be raised. Only if they think the grade should be raised do they then take the card out of the case and put it in a new one.
In short, they can see the old grade. I’ve had success with both cracking cards out of the case and sending them for review (still encapsulated)."*
Reviews are done in case. Sometimes they remove them for an upgrade and notice a surface scuff or the like then recase it in a new case but with the same serial number but at the original number.