There are some 4k projectors I'm looking at for this purpose that could be bright enough for my needs and detailed enough at sizes that work for head to toe filming (maybe 18 feet by 10 feet ish). Really interested in seeing this develop. The advantage to the LED screens is the ability to create a sort of crescent/cyc shape. Rear projection is going to give you a flat surface.
200 takes over 5 days is 40 takes a day. Assuming 10 hours of shooting per day, that's 4 takes per hour. For a complicated party scene with multiple actors. That....doesn't seem like an especially torturous work environment. That seems like he's moving at a modest pace so as not to overwork people. We also have no idea how important this scene is in the film. For context, the opening of The Social Network (in the bar) took 99 takes over two days....and it's brilliant.
It's frustrating the way they try to limit this, but it's an easy thing to fix. In Premiere, just Interpret the footage as 24p. It's rare your drone shot would have dialogue sync to worry about, and the stretch from 25 (or even 30) to 24 is minimal.
You're missing one very important thing:
Drones 250g and over need to be registered/licensed.
This is 1 gram under.