It seems feasible. I’ve noticed for example my Canon R5 autofocus in videos can pretty consistently hold focus while zooming. One thing to keep in mind though

It seems feasible. I’ve noticed for example my Canon R5 autofocus in videos can pretty consistently hold focus while zooming. One thing to keep in mind though is in big production sets they are not using automatic focus at all, and cinematic lenses don’t tend to have focusing motors. (Also a focusing motor for a 100lb lens would likely be very noisy).