Meh. Seems unnecessarily confusing, and a visual distraction as you scroll up/down note that happens to move all headings on/off screen.. And for what benefit?
One corner case I stumbled upon was notes that do not have any headlines. The plugin panel was blank and I was (shortly) confused 
Thinking about pluma9's proposal, I thought maybe in this case the panel could be hidden. However, if a panel is not displayed where I'm expecting it, I'd probably be confused as well. So my vote goes to not hiding the panel (or make it optional).
1.1.6 supports clicking on the header to scroll the note to the top.
Great plugin!
I searched this thread but couldn't find anything about the toggle icon. For me I'm seeing:
So that's: sidebar, notelist, and outline.
could the outline icon be something like
Maybe inverted so it looks more distinct?
Am I correct in understanding that this plugin does not pay attention to the userchrome.css file?
I ask because I'm on a small laptop and, to me, there is way, way too much margin between the toc items:
If I was only using the touch screen that would be good, but I don't see why this much of a gap is needed between items.
I wonder if it would be possible to make the toc panel a "fly in" when the right side border was touched with the mouse? the [toc] table of contents can be done that way using css, but alas only for a rendered note.
How to change the background color?
A suggestion after seeing a recent update from the Favorites plugin:
would be even better if the 'Outline' header was fixed and always visible when scrolling through the headers list.
This is a great plugin, but for some reason it opens the outline panel whenever I start typing or switch between headers. I can toggle if off, but then the panel opens again on its own. Is there a way to disable this feature and only have manual toggle?
This is a bug, I will fix it as soon as possible.
Thanks for the plugin! 
I moved its pane to under the note overview pane. This pane can be hidden by pressing F10. However, the outline remains visible. Is there a way to also hide it with this shortcut?
1.2.0 fix it.
And thanks for adding the shortcut key 
how can I change the background color to match my style?
Windows 10. Joplin v1.8.5 Outline v1.2.0
I have had an issue recently and I am not sure when it started. I set Outline to occupy a relatively small column on the right of my screen. Whenever I switch folders or restart Joplin the Outline panel is set to about the same width as the main text window. When I reset it to the width that I want it works as long as I am looking at notes in the same folder, and then reverts to being far too wide as soon as I switch folders.
Do other people experience this? Is it a bug? Is it something about my setting?
It makes reading through a lot of research documents an unnecessarily painful experience
V1.2.1 can modify the background color.
The best way now is to try to put the outline panel on the left side of the notes panel. There are many strange problems when the plugin panel is placed on the far right.
Okay, that works! I did like it on the far right though 
how? I want it to look greyish like joplin. seen here A markdown outline sidebar plugin for Joplin - #90 by itge13
also are you aware of column width resetting? I have it left below my notes and everytime I go to a note with no outlines it resets it afterwards to half size.