Extraneous menu ornaments in every menu.
Every item in the popover menus has an ornament (colored red here to demonstrate) for the radio option regardless if the menu itself uses a radio option, this adds extraneous padding to every menu and submenu that needs to be worked around in the stylesheet. Correct me if I'm wrong but as far as I can tell the input switcher is the only one that has the radio option.
I've undid the stylesheet overrides here in the system menu to demonstrate how often it is adding unnecessary padding and making popovers wider than they need to be.
It'd be nice to rework how popovers display and/or draw radio options so all these aren't drawn in every menu and the stylesheet overrides can be cleaned up and popover item padding can be made saner.