My very uneducated guess is that you'd be fine. I had a CCV top with a roof air unit (#100?) and the fantastic fan (very little weight) and a small rack and it lifted fine. Derek didn't have a number answer for me back then but said he trusted the motors he used/uses and it might just need a little help getting started, a small push from completely down where the most stress is. Mine didn't, it lifted fine. It all depends on what you keep in that roof box though. Bricks might be a bad idea. Light gear a good idea.
You could, of course, just call them and get the actual weight limit. They're a lot more organized these days and you should get an immediate answer on the phone with a person who should know.