I love the new minmalistic UI.
The Show/Hide Tree icon on the far left is placed exactly as it should … and so should be the Inspector icon = on the far right. Scrivener uses the same concept for showing/hiding the binding and their Inspector.
Since the Sync button stays out because of its color it is not necessary that it has to be the most right icon.
Understood, but also like every other app you can customize the toolbar order: Control-click on toolbar, choose Customize Toolbar.
I realize you’re probably suggesting this for the default toolbar look (and seems reasonable enough), but also easy enough to fix right away according to your own preferences.
Placing the Inspect button at the far right is symmetric with the Sidebar button at the far left, and more consistent with Apple apps like Keynote.