ok, thanks. as per V15 manual "Media Pool improvements include new editable Clip names by default and larger thumbnails"
except its not turned on by default in last view. 1st column is File Name
thumb view displays File name, not clip name. its not editable, there is no contextual menu to rename, there appears no way to change the clip's display. you have to rather unobviously go to clip props to change it

likewise in the TL File name instead of clip name is displayed too.
so there are a few bugs here to sort out to conform to the manual....
S