The width of columns often doesn’t suit the content. Titles are cut, numbers are not visible. This problem occurs in usual list views, but also in lists included in form views. An easy solution was to have a simple handle.
On TUB23 we saw a good way in adding a corresponding extension (using javascript and css). Kalenis already a similar solution, but that was done in way not preferred by the core team.
Here a screenshot showing the problem and a mockup with the solution.
After that discussion, I think @htgoebel and I found a very simple solution:
columns containing numbers should always be fixed to minimum width (with a little space before and behind of course), there is no use of manually making them wider or smaller,
if there is a saldo (total) column right edge, it should always be visible, no matter what,
text columns can be changed in width, only those change width with change of the menu column width.
This solution was not possible before because columns could not be made invisible. But now they can, so if a window is too crowded, user can just uncheck certain columns instead of messing around with sliders.