The marker window currently displays in the format of the main ruler.
As a TV composer I have a Bars and Beats ruler when writing for musical sense but my marker track is set on the linear timebase and isn’t tied to musical time so it would be way more useful for the marker window to display non musical data e.g. timecode/seconds etc.
At least give the option to either customise the format or to display in primary or secondary time format as you do with the main time.