I'm picky about how often Jackson is jumped. We have a lesson once a week and are jumping 2'9 - 3'0 but other than that we do flat work through the week. If my coach asks me to school a specific exercise it's done with cross rails or little verticals and if we don't have a lesson during the week he gets that time off jumping. He's nine years old, so it's not that I'm worried about immature bones, but I want to keep him sound.
NOW, I'm looking to 'lease' him out a couple days a week come September. I wont charge, they can ride for free as I'm just looking to keep him in shape while I'm in school and was debating restricting whoever rides him to flat work. Would that deter you? Do you think it would be detrimental to allow them to school him over fences (provided they're good enough riders to jump him, I'm a fussy horse owner)? How often is 'too often' in that it begins to start damaging joints?