(macOS) Two windows side by side: is there a way to allow stretching one window to minimum width?
You can do this with Applescript. Set the boundaries for the front window to be a certain width. Then after clicking on the window you want to shrink, run your Applescript. Name your script something like narrow_front_window.sc.  The script could look something like:
tell application &quot;Finder&quot; to set the bounds of the front Finder window to {36, 115, 511, 674}
Just run the script after bringing window to the front.  The widows do have a minimum size.