Seeking wisdom from those who have installed a lift

I have never installed one myself but I have plenty of neighbors around work that have them. Some have gotten lucky with concrete being thick enough to just drill some holes and drop studs in the ground and call it a day. Others have found their concrete to be only about 3 inches thick so they end up cutting squares out where the posts will mount, digging down, and filling back up with rebar and concrete.
In the end, just to state the obvious, the main thing is to make sure you have a good foundation for the posts. As far as the gantry, I would say it would almost seem advantageous to just install a 2nd one on the other side of the shop so that both bays can have their own and you and your neighbor can share them depending on the jobs you are both running.