Just wanted to share my personal insights/ideas for managing the column width. I could imagine another setting for "Width", that has the same capabilities as other fields, so you can adjust it based on variables.
Default options may include: Auto, Maximum, Minimum... and Custom, of which the latter actually refers to the FX button - this would allow you to set a specific number of pixels (potentially based on the column name).
Please see the fictional example below:
P.s. Other thoughts aside, I do think the issue in general should be getting top priority. And quite frankly, it doesn't sound too complex.