For me, this flow is quite an intricate procedure. The two singers will eventually have stemless notes to indicate free rhythm, but the accompaniment needs to stay in common time for a number of bars at a time. So far it’s worked fine. But when I get to the first ‘regroup’ bar (bar 11 here) I can’t give the singer a common time bar’s rest. The Ab in bar 11 is just a dummy, which I created in the hope that deleting it would show a corresponding rest. But, as shown in the video clip, it doesn’t.
I did find a similar question in the forum, to which the solution was to toggle the ‘Starts voice’ switch, but I can’t get that to work in this context. BTW, I’ve worked only up to bar ‘10’ (though I suppose it really should be 13 as far as the accompaniment is concerned - I’ve only just noticed that), and only in one stave (the upper of the two vocal ones), but I had prepared a 16/4 signature in bar ‘12’ in order to continue, when I spotted the missing rest issue.