I was surprised that I haven’t thought of or seen this request before, but it would be really nice to be able to (while in a custom split note pane layout), toggle the current active note to fill the entire note pane region of the interface.
It would keep all other panes (file explorer, backlinks, etc.) in place; and when you were finished working on that single note, you could toggle back to the exact custom pane layout you were in.
It might also be nice to have it set up to remember that original layout even if you decide to split and rearrange while in “single” note view. However, with this, the feature might need to distinguish between using the toggle and the back and forward functions.
For example, if you toggle between views it saves the custom layouts of both, whereas if you use the back function while in single view mode, it brings you back to original custom layout and clears your custom single view mode layout.
I guess really, it may be better to just call this a custom layout toggle, but I will leave my description as is for now.