First time I'm writing so, first of all thanks for the show and the space here to talk about Linux and FOSS, it's really great!
I wanted to mention org mode for note taking, although it might not be what Leo is looking for, is worth having a look at it (also in case you really go for the history of note taking apps).
Org mode is the favorite tool of Emacs geeks such as me. Check out the link, it has pretty nice features: markup sintax, organization and agenda, code blocks with sintax highlighting and executation, export to several formats like html, pdf, odt... and a very long etc. Of course, all works well within Emacs. However there are more and more tools external to Emacs that deal well with it, for example github, gitlab and codeberg render it automatically like the markdown files.
About the portability, there are several apps created to deal with it. The favorite for mobile seems to be orgzly. Although I prefer and use Zettel Notes, which could actually be a potential app for Leo.
Zettel notes uses markdown as default but it accepts also org and txt. It has great organization of notes, tags and links. You can add audio, self recorded included, video, whole webpages, etc. It has capacity to link via git repos, nextcloud, google drive and others. And my fav, allows different types of encryption and password protected, including GPG using personal keys.
I have my notes in org mode on my personal and working laptops on emacs (which BTW on windows is great because it gives a Linux-like-feeling) and synchronize it to the app via git, with a few sensitive notes encrypted. It works great for me but of course, it requires some work for setting up. But since you are thinkerers, I thought you might like to have a look at it.
Good luck and let me know if you did.
Hey, it seems that the channel is dead, I'm checking old posts out of curiosity and happen to know a thing or 2 about your question.
It seems to me that your configs are fine, but you are missing a way to enter the undo-tree visualizer. It is bind to
C-x uby default. If you want to re-bind it change ofundo-tree-visualizdto a global keybinding and you can then use it.Id recommend you to stick with the option nr 2, using use-package and :bind, it's the cleanest.
Let me know if you still can manage and I'll try it myself before answering again.