Yes, it can be done, at least for basic editing, this is an example of 2 4K footage, trimmed, added transition, title and color adjusted within LumaFusion and it works.

Both of the Mavic Air footage are 3840×2160 @ 23.976fps

I used LumaFusion https://luma-touch.com/

I uploaded the clips into google drive (dropbox is not working at the moment for me)

I imported them into the app

Create the frame sizes you want (in my case 2.35:1)

edit away

You can export 4K or any lower resolution and quality 🙂