But why not simply use the available space in the header?
The timeline will usually be quite thin or even completely collapased to the header, like for example in the Animation, Motion Tracking and Video Editing workspaces.
So users would have to make the sidebar taller in order to use it.
Usually the timeline will be quite long, there is plenty of space left and right of the playback controls.
Why not put those menus there?

In T57895#555078, @Sebastian Koenig (sebastian_k) wrote:

But why not simply use the available space in the header?
The timeline will usually be quite thin or even completely collapased to the header, like for example in the Animation, Motion Tracking and Video Editing workspaces.
So users would have to make the sidebar taller in order to use it.
Usually the timeline will be quite long, there is plenty of space left and right of the playback controls.
Why not put those menus there?

I agree 100%.
Settings that are used very often should be available in the header. Makes no sense have those settings in the sidebar... totally no sense at all.
Things are becoming very hard to find for no reason imo.

I agree with adding these items into the header. Putting them into the sidebar to keep the timeline clean, would make for a less clean workflow.

It also wouldn't solve the original cause of this issue, that the settings are not available at a glance, but need to be accessed through menus, submenus, panels, sidebars.

In my use case, I have the timeline editor completelly collapsed, other than its header. This way I can very easily and quickly access all of the required settings.

I have used keying set for rig properties (which drive shape keys or bone transform)
Then hope blender 2.8 offer those keying-set menus in side bar of Time line, and Dope sheet ,with add more options.

(eg we need to use Scene property editor, to add keying- set, but it is for animation. maybe it cause no problem,if keying-set option are located in Timeline, Dopesheet right side bar too (at currrent there seems no menu) with option to filter visible keying-set.

Then at same time hope return simple keying set options,(add remove, and chose keyiing-set) with auto key , in header .( as same as 2.79) actually it is most often used and can access easy. I could easy understand, how it may work.

Though current drop down menu is good design, but actually it is not good place for key-ing set options I think.
(I serched around, where add keys for current keying set,, today,,) and I could not find the + and - icon replesenet button to set keys of keying set for a while.

I've tried to re-arrange the header in order to add back the keying sets.
I've tried to keep it balanced, without adding too much stuff; I'm not an animator though, do you think that something like this could work?

Ideally I would put the playback buttons in the middle like this, but I don't know how to do it, having a layout.separator_spacer both before and after doesn't work as I would expect.