But AFAIK all apps/programs that have builtin conversion to text are closed/proprietary.
xouranlpp is note taking like on paper or a white board like the reMarkable has.
Also you need a digitizer. The touch only kobos are too low resolution. Curiously the Libra 2 works with a pen, so you can take notes and save (but not edit a saved file) on Sketchpad.
The xournalpp might be some value on a Libra 2, but as I have a Sage and the notebooks export in various formats I'm not fussed about nebo being "closed". If I didn't have a Sage & Elipsa I might be curious to try xournalpp on the Libra 2. I can't see the point of it for other Kobos that don't work with a pen, or have nebo.
Edit
I'm on Mint 21.2 "Victoria" which is like Ubuntu 22.0 "jammy" for installs, so I'll try Xournal++ on my Linux mint which has a Wacom USB tablet (very like the earlier serial model).
From
https://sourceforge.net/projects/xournal.mirror/
Actually The installer tells me my distro has an older version, and that is a better idea, then it tells me it's already installed.
It's pretty and on desktop version lets you switch to keyboard.
It's ultimately a sketching application organised like a notepad, just like the reMarkable, so not a true pen based note taking app at all, since for 20 years, those convert either handwriting or custom "graffiti" to real computer text.
I realise I looked at it before.