There are currently three System Dividers options:
Two of these (“Never” & “When number of staves differs”) apply to an entire project, but “When minimum number of players present” is on a flow by flow basis. Once you fully understand the sequence of operations it’s fine, but this behavior is not obvious the first time you use this option.
Suggest that some wording be added to this panel to clarify the behavior. It could be something like “When minimum number of players present in a flow” OR (if that takes up too much space) simply “When minimum number of flow players present”. There may be other phrasings which are better.