My biggest curiosity is how easy it hard it will be to use their UI widgets for third party software and release on other DE.

I like the idea of writing more apps with Rust and if the ergonomic fit is better than alternatives, this could be a great way Forward. Bridging themes with gnome/gtk in the other direction likely a necessity for that use case.

My only other concern is getting kde tray apps to work out of the box. With budgie/Gnome, I've had to install an add on for that.

Not that I have a lot of things needing the integration. Variety and Dropbox being the main ones for me.

It's also annoying when Windows don't have a corresponding handle in the taskbar.

If they deal with these annoyances well, I'll be more than happy with the next Pop release.