Yes please - I'd really like fullscreen preview!!!!!!!!!

Please consider adding a destination-contextual preview. When I'm working on a video I would like to see how it might look on TikTok with it's right sidebar, or in general on mobile. I envision it working something like a brower's web inspector device selector, but maybe a bit simplified. Raw preview would be a great start, but making it feel like you're experiencing the media on a few types of devices and services can be very productive.

Yes - this a major missing piece. You want to know if your images are going to be the right aspect ratio, work on smaller monitors and just plain get rid of all the screen furniture.

Even better would to define an dedicated output on the graphics card for the fullscreen feature

I used to be able to do full screen in the classic version. Why not now?