I agree with that whenever SQ can be affected, but making thick chasis just to protect the amp during the shipping seems to me unreasonable - just pack it well!
We've always packed our equipment well to survive FedEx/UPS treatment. But experience has shown that even though its packed well, the chassis can be deformed by the mounting bolt for the transformer if the transformer is heavy enough and the chassis thin enough.
These are the claims of customers- they prefer the "sound" of certain op amps over others, not mine!
If that is so either the opamps were really terrible or the designer didn't know what he was doing! With any module you really don't need a lot of gain, so why would decent opamps affect the sound?? Answer: if the buffer is properly designed and if decent opamps are used, they won't.