If I might get back to part of original question at top of page. Cautionary time sigs at end of flow are needed if some staves need to be hidden in the next system. Maybe I’ve missed something but the only way I’ve found to do this is by splitting the flow. Right now I’m working on the vocal score of an opera. Several scenes start with a page or two of piano (orchestra) only, and then twelve singers enter. If there is a change to time when they enter then I lose the cautionary sig which should be at the end of the previous flow
Actually, I’ve found a way to do it: add an empty bar at the ends of the first flow and hide the rest. Remove the barline. Enter the new time sig. Change the bar’s width to an appropriate size. I suspect it will screw up playback.
Is there an easier way of doing this? Changing layouts won’t work because any new layout starts at bar 1.
Apologies if I’ve missed something obvious