I'm not sure if that helps you, but there are plenty of search focused launchers for android that let you add keywords as tags to apps as well like KISS Launcher and Kvaesitso
Another point for KDE might be that it works much better on a small screen that may be partially obscured by an overlaid keyboard. I used Bazzite Gnome for a while on the Steam Deck and I much preferred Plasma on there after switching back, despite using Gnome on my main system.
Sounds great! Still waiting for the self-hosting option though. Even with e2ee I don't like giving control over my notes out of my hands. And locking things like Tags and Markdown export behind a subscription does not feel like a future-proof solution.