I've been inserting such groupings by writing down the grouping and changing the tempo in that place to allow the grouping to fit. Any other notes contemporaneous with the grouping have to be lengthened so that their tempo doesn't change. But since I'm new at this, I don't know how to do all this on a hidden staff and show the correct printed notes on the display staff. Any suggestions on how best to do that?
For pentuplets, every "ordinary" note being played concurrently with the pentuplets needs to be lengthened by 1/4. On the hidden/played staff, tie each note to one with a quarter of the original length (or add two flags). E.g., a dotted eighth would be tied to a dotted 32nd and a 16th would be tied to a 64th. On the displayed/muted staff, no ties would be needed, but each note would be followed by a hidden rest
with the same duration as the new notes following the ties in the played staff.
Also check this tip:https://www.noteworthysoftware.com/forum/?topic=2326