I’ve discovered that it is possible to create a cautionary time sig and key sig at the end of a flow, should you need it.
- Select the final barline of the flow.
- Change it to a thin double bar.
- With the bar line selected, add the time and/or key sig change.
- With the bar rest selected, use the Shift B popover to delete the bar. (-1).
EDIT: This may be a bit unstable and not recommended…