I did all my editing at 1080p, but I didn’t have as many effects changes. It’s really up to what your source materials are. If you have all 1080p sources, there’s no reason to downscale other than perhaps render times. You’d still need to mask out pieces the same way, and having more pixels to work with will actually make that easier since you can see more detail.

If you’re doing a lot of zooming, it depends on how drastic the shifts are. If you go really far in, then yeah, I could see the justification for lowering the rest of the movie to match better. If it’s only like a 10-15% zoom you might be able to get away with it on a 1080p sequence by using an unsharp mask filter or something similar.

That being said, I know Adywan is editing at 720p so that he can integrate lower-resolution sources like the GOUT and whatnot, so that’s a perfectly valid reason to do so.