That might be helpful, although it may eventually backfire if ds7 ends up loving his skip days and wants to do it more often. Would partial homeschooling be an option (sort of what it seems like you're wanting to try), or has that been dismissed by the school as well? Also, do you have any after-school or weekend opportunities available (talent search...)?
DC20 tried this approach over the years, but it would sometimes backfire and make the situation at school worse. However, provided you monitor his attitude after trying it a few times, it seems like a solution for now. Good luck

It sounds like a difficult situation...