Thank you for your kind words!

Currently the folding-status in the navigation panel isn't persisted (in memory between note changes) and I'm not sure if this could be done easily, since the structure is generated every time you type into your note and it can change all the time.

And to persist it on disk for every note would be even more work, since notes aren't persisted in a disk-database in QOwnNotes...

I unfold the parent heading. All children subheadings (H2s in this scenario) are now folded.

are you talking about a "fold / unfold all" feature?

I don't mean persistence (I don't think it would be that much useful). If I could do the following:

1. select the note in the Naviation Panel.
   

2. click the little triangle to fold the 'note tree'

3. click that triangle to unfold the 'note tree' for that note
   

4. have all the subheadings for that note folded.
   

No persistence needed :-)

Is it correct that you want to be able to fold the sub-items of a headline by fold the headline?

But what would be the help of this if when you type a single character everything will be unfolded again?

It's no problem if I can fold subheadings by double-clicking its parents item 'triangle' (or by any other shorthand).

I see this feature useful for reading older notes, rather than for editing notes.

It would make possible to use 'Navigation Panel' as table of contents for longer notes. Now, when you have a lot of subheadings, it's rather difficult (the list is very long and you have to make a lot of scrolling). When you have few subheading, Navigation Panel is not that important at all, you can see almost everything on your 'Editing Panel'.

And I don't insist by any mean that this is 'generally' good idea. I know that it took great effort to design such a wonderfull app. I understand, that what I see as a useful feature might be for example a bug for seasoned developer. 'Navigation Panel' is still a GREAT, GREAT feature.

I'd rather fancy a context menu where one could fold or unfold subitems.

It would be great!