Well BP's will never enjoy being handled, but most will tolerate it.

An hour seems like a bit much, but as long as he is still eating and shedding properly then I don't see any issues. You need to keep an eye out for signs of stress (bad sheds, overly active during the day, not eating, etc.) If you start seeing these signs then you know that you are handling him too much. Other than that starting with short sessions and then progressively longer sessions sounds like a good plan. I would start tonight with a 10 -15 minute session instead of a 15-20 minute session.

The better your husbandry is the more likely that he will adjust to being handled.