If not I can probably create a new text style that attaches to the system staves in the score but in all of the parts - sounds like it would be based on the Tempo text.
Don’t think it is possible, but it is an interesting idea.
Do you envision this as something to be shown or hidden (via Properties?) on select measures or universally displayed at every time signature change (hidden or displayed) for an entire flow?
It would certainly be nice to see it in the properties, then you could have control over which time signatures that you wanted to display the groupings above. If for some reason you wanted all time signatures to display it, you could always choose Edit > Filter > Time Signatures first.
One of my clients writes in such a way as to change not only the meter but also the pulse quite often, so it would be a handy feature. Perhaps a feature request.