Combo boxes are unnecessarily wide

Summary:

Inkscape's combo boxes, most including a three-point decimal place, are already roughly 20px wider than necessary, eating a lot of space that could be utilised by smaller monitors/resolutions.

Visual Aids:

Inkscape on macOS

Minimum window size

macOS Theme Preferences

Inkscape on Ubuntu 18.04.5

Fullscreen window

Ubuntu Theme Preferences

What happened?

On macOS, the minimum window size to see the entire Inkscape UI without Reveal arrow icons is 1252x980. Much of the horizontal space are the Tool Bar's wide combo boxes

Inkscape's window on Ubuntu, discounting the GNOME Dock and Topbar, occupies 1300x740px. Yet being slightly larger horizontally than the macOS minimum window (1252x980), the Tool Bar has a Reveal arrow icon at the right. It appears the GNOME combo boxes are slightly larger.

Inkscape on Ubuntu has Theme Preferences set to use "smaller" icons. Nevertheless the Toolbox also has a Reveal arrow icon at the bottom.

Why this discrepancy? They're already wider than needed on macOS. On Ubuntu/GNOME they are even wider.

I've taken the liberty of shaving pixels off of the widest toolbar in macOS Inkscape, the Text toolbar...

• Before...

• After...

40px removed from the font-family drop-down, 20px removed from the font-style drop-down, 20px removed from the font-size drop-down (20px more could have been removed as it's highly unusual to set a four-digit font-size). 80px total removed and no drop-downs were harmed in the process.

Tangential:

• Is there an Inkscape .gtkrc or similar file to change, among other things, Dialog Panels' font size?

Version Info:

- Inkscape Version: 1.1-dev (1b8854aa56, 2020-10-10)/1.1-dev (1b8854aa56, 2020-10-27), snap package/1.0.1(1.0.1+r73+1)
- Operating System: macOS 10.13.6 (17G14033)/Ubuntu 18.04.5 LTS