Cryogenic treatment; who’s used it, or share some hearsay

We have a couple facilities in the Phoenix area that I grabbed quotes from. Average price for a block with main caps was $350. One facility quoted me $420 for block with caps, rockers/shafts and valve springs which is the route I’ll likely go. All of them recommended the parts be final machined before treatment otherwise you’re re-introducing stress that the treatment is meant to relieve. One facility which also incorporates a machine shop further stated that treatment before machine work would cause excessive wear on the shop equipment.

Also, piston manufacturer advised against cryo treatment on pistons or rings. My worry is that cryogenic block treatment is said to reduce sleeve expansion from heat. In that case could I be looking at piston to wall clearance issues under heavy load? Piston end gap?