We do know this issue exists and will work on some solution.
It seems to me that all what's needed it to take the date string, measure width for current font (I remember there was some Windows API function for it) and adjust column width accordingly. Do it once when WinBox starts and problem solved for any possible font.
No, it is just a special case of a problem occurring all over the place, and the length of the formatted string depends on the actual content.
It is extra annoying in this case because the user cannot change the column width in the log display (fix that!) but it also occurs in dialogs where it is not a column.
The whole user interface does not scale.