He doesn’t need a Clyde bike, any reasonable quality hardtail will shrug his weight off. Speaking as a big’un myself, I rode an entry level bike for two years without any weight related issues and I was quite a bit heavier than your friend through that time.
Issues most likely to crop up with a square taper bb, cheap spokes/rims and possibly fork if it runs coils, but I’d let him have at it and fix problems if and when they come up.