Yes, and that's the number he's trying to find out for his forks
I'm saying there is a spec'd maximum size that the manufacturer says you can use, and that they will have tested to make sure that this size is ok to use without tearing the fork apart
A bigger rotor isn’t going to tear the fork apart. It might mean you have to stack 2 adapters which isn’t the wisest idea though. Normally I wouldn’t gor for anything more than whatever is native +20mm.
The caliper won't move far enough out to deal with a bigger rotor?