When they are younger they climb a fair amount, but once they are a couple years old and a couple thousand grams, I feel like they become less adventurous.
Sure they can climb fairly well, but what they lack is a good grip like arboreal and semi arboreal species. They just don't seem to "hang on" very well. If you want to throw them on a perch, cool, just make sure it isn't too far off the ground and maybe make a "landing pad" in case they do fall. Perhaps a towel or something.
Ball pythons aren't super fragile creatures. A short fall shouldn't be too bad, worst case scenario being a broken rib or two (ouch). They are tough little guys.