oops part of my comments to yours are considered as quotes... A workaround 'solution' could be to have a First space placeholder with no button, same color & high as the window title. That way, the window buttons would be a bit too to the right, but all hierarchies would be visually consistent. (and I hope it's easy to implement)
Bug 1817673 Comment 4 Edit History
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A workaround 'solution' could be to have a First space placeholder with no button, same color & high as the window title. That way, the window buttons would be a bit too to the right, but all hierarchies would be visually consistent. (and I hope it's easy to implement)