Hey, same boat. I’ve tried FreeCAD and Ondsel (which is supposed to be a more intuitive version of FreeCAD)… But they are both so unintuitive that it drives me nuts and I just boot into Windows when i want to design something functional to 3D Print.
Luckily Blender works great on Linux for less functional designs.
I was using Joplin for a while… Self hosted their server. On two occasions it screwed up on me and wouldn’t load my folders… Luckily I had backups but it was still frustrating. I don’t recommend them purely because the notes are stored in a custom format instead of just plain text files.
My favorite way of doing notes now is with git, currently using a free private repo on gitlab.
Just clone the repo on whatever PC I need them and it has backups and version control.
Then use GitJournal on my phone.
It’s perfect for me. I love it.