Visual noise in Firefox UI after removal of inner window gaps of floating chrome for Nova

[Filippo]

Recent removal of inner window gaps of floating chrome for Nova has caused some visual glitch: using 3 different colors for title bar, content area border and tabs container (when configured as left or right) causes "visual noise" near the rounded content area border.
 

In the second image, title bar seems to "lose" a pixel in the right side.

With old theme, this part of UI was way lot cleaner.

I filed a bug in BMO (Bug 2066519), but it was closed as wontfix.

I hope someone in Mozilla reconsider this decision and fix this part of UI.