As a note, my plugin, Collapsible blocks, does add support for automatically making headers collapsible in the unreleased in-development version. It does so without any additional markdown, and is visually extremely unobtrusive.
I’ve additionally already had it on my todo list to investigate if I can make this work in the WYSIWYG editor - up until now I’ve completely ignored that editor in my plugins. I can’t guarantee success on that front, due to a total lack of familiarity with what it’s capable of, but we’ll see. I do not have a timeline for when I expect a release - my coding comes in inconsistent bursts and I’m easily distracted.
The header-based collapsing code is actually already working (in the webview), but I’m like 60-70% through a different feature that will continue to delay release for a bit longer. That other feature is allowing for the markdown-defined collapsible blocks to collapse in the editor as well as the webview - plus a bunch of polish and refactoring.
Out of curiosity, what’s your expectation for whether header-based collapsible sections should “remember” if you left them opened or closed when you leave the note then come back to it later? Should all header-based collapsibles always start open, or should they remember how you last left them?
I had been mulling over whether to add in a way for them to remember, but wasn’t really happy with any potential solutions I was able to come up with. Is that something I should give more thought to, or not really a big deal?
Also, apologies in advance if I fail when I move on to trying to get it all to work in the WYSIWYG editor. I don’t use that editor myself and don’t know its capabilities, and so far as I’m aware my blocks currently render in it, but aren’t functional.