When I said Nextcloud-like, I meant in function and not philosophy. So Nextcloud-like in the sense that you can do file sync, auto uploads of videos/photos from a mobile device etc

Maybe you should give Ubuntu Server a spin. Last I tried, Nextcloud snap was the easiest way to get Nextcloud up and running.

DivestOS is the only Android ROM I know of that integrates the Mulch webview. But Tad (DivestOS dev) also builds standalone binaries of Mulch that can be installed independently- just add their repo into f-droid or something like droidify and you’re good to go. Link: https://divestos.org/fdroid/official