If you are used to ubuntu then you’ll be fine just to go with that again. You can get minimal iso images I think, or KDE Neon is quite minimal. You could add the kxstudio repo for plugins and you’re good to go.
I recently installed manjaro on a laptop and I like it but there is an issue with some plugins. I use the kxstudio repo for plugins in KDE Neon and when I install the plugins with AUR some of them are not seen as the same as what I had used in old projects so I can’t load them properly. Might be something to keep in mind.
I recently installed Manjaro (Budgie desktop) and after a few tweaks, it’s the only distro that has not given me audio glitches on my laptop. I guess it comes down to using a very recent kernel.
In my main computer I use Ubuntu Budgie. It’s very light. But in Ubuntu I still have from time to time problems with the audio when using Rack and the ES-8 audio card. Sometimes it works, others is full of glitches.
If there’s enough space on your hard drive, create an extra partition and run some tests, so you can turn back to your working system without any issues.
I recently upgraded to Ubuntu-studio 21.10 and it still feels like home
If you are willing to spend time on configuration Arch Linux is very lightweight as it comes with the bare minimum and you can install only the things you need. It has extensive documentation, a fairly large userbase, good package system and frequent updates.
Note: I’m mostly on Windows 11 now - no working drivers for my main Audio Interface (M-Audio ProFire Lightbridge) in linux. Considering RME Digiface USB instead.