Although a $6-700 gantry is a huge investment, and makes more sense for a professional outfit (planning for the future), I have read many times of issues using "cherry pickers" on sevens that have been problem fraught. I saw how one fellow had to extend the boom so far, the rear legs needed extra weight added to keep from tipping.
It would probably less of an issue for 7s up on wheel ramps where the legs can roll between the wheels, but chassis stands tend to get in the way.