I'm a new user of Inkscape .92 but very long time graphics user (pixel, vector, 3D) and would be a better user if the UI was more customizable and so suggest these possibilities for change, or at least user options:
Ability to move tool panel from being stuck at left edge to floating so we can put it where most useable. In all my programs I keep it near right edge of main screen.
Ability to move toolbars on top.monitor screen wide enough to have both toolbars on one row instead of 2 rows
Allow for use of color palette to be floating. and able to roll-up to a simple panel row; maybe even on toolbar row with dropdown arrow click
Probably most important would be ability to drag any panel (or toolbar that changes into a panel) onto a second monitor. I normally use main monitor for workspace and tool panel and remaining tools/panels/etc. on the second monitor.
All of above lends toward better efficiency and full screen use of workspace for artboards.
Thankfully I can make the program window wide enough to let part of it on second monitor in default mode now.
Doug