Thanks for linking @argentum. Furthermore, I’d like to point out that this plugin solves many (not all) of the problems indicated in the OP of the thread:
Do not break it with each release of Obsidian
Well, that remains to be seen, but I’ll try my best
Toggle Andy mode by keyboard.
I added a command to the plugin so you can toggle it with the command pallete, or assign your own hotkey to it.
Keep it independent option of light/dark theme.
As a plugin it’s now independent of all themes! Yay! (Though it may not work the best with some themes currently)
Navigate panes (scroll horizontally, go to first/last) effectively by keyboard
Some hotkey assignments do currently exist (next/previous pane for example) and the plugin scrolls to the focussed pane. So pending more navigation shortcuts in Obsidian itself (or other plugins) this is taken care of.
Reorder by dragging also among panes nested on the left side (which show only the filename vertically)
This is the big one I want to tackle now that I have javascript capabilities in a plugin. It will come in time, but currently works the same as the CSS version (i.e. not very well)
Unfold any folded/nested pane (scroll to it) by clicking on it’s vertical bar
As stated above, active panes get scrolled to, so now clicking on a pane’s vertical bar will scroll to it
Allow to nest panes also on the right side as in original https://notes.andymatuschak.org/
I’ve done this in the plugin, too. Though my implementation differs slightly in that the right side titles stack, whereas Andy’s do not. There are both pros and cons to this approach, and I may include options to tweak it later down the line.