If you want your connectors to look somewhat factory, and are tearing the car completely down to the chassis and putting it on a rotisserie I don't think they're a bad way to go at all.
I definitely wouldn't install frame connectors while a car is on the rotisserie. In my opinion you want it resting on a level surface and fully supported or I think you could "lock it in" to a slightly twisted position. I could be wrong but I've seen how door gaps change while a car is rotated around on one.
