SplitButton & ToggleSplitButton: Incorrect tab order

[Athari]

When pressing the Tab key on a page with SplitButton or ToggleSplitButton, first the arrow button is focused and only then the main button.

I think the correct tab order should be the opposite of that, consistently from left to right.

[rabbitism]

This likely is caused by the order of elements we placed inside dockpanel. Is it even possible to change tab order in a panel?

[Athari]

I've tried changing tab order with InputElement.TabIndex property, but all I got was first all main buttons being cycled, then all arrow buttons. In the end, in my implementation of split icon buttons in Ursa, I gave up and switched to Grid panel.