Early music features
One way to make use of these symbols is to replicate when composers of the renaissance had multiple voices in different time signatures simultaneously without using tuplets. Edit the time signature on a per-staff basis, as long as the beginning and end of a measure in all staves match up. If they do not, then consider increasing the size of the measures to the lowest common denominator.
If we refer to the next illustration (De Profundis - J. Des Prez), the description is:
- outdated since now getting beats with different tempos but coincident amplitudes is very easy via the "Local time signatures" feature https://musescore.org/en/handbook/3/time-signatures#local-time-signatur…
- out of place because here the measures with different times coincide in width.
If, on the other hand, reference were made to e.g. Ockeghem's "Missa prolationum" (see e.g. https://en.wikipedia.org/wiki/Missa_prolationum) the above description might also make sense but the illustration would be out of place.
So the question is "what are we referring to" and, consequently, possibly develop the "Ockeghem" case history by reporting even just one more illustrative example illustration.
I think the handbook was written while MuseScore was at an earlier version than the current one. In these days on the other side of the pond we are revising the translations of the terminology (Transifex) and someone competent translates and edits the handbook (/it) trying to make it more adherent to 3.6.2.
So here I am being a spokesperson, RSVP