I write music with plenty of time signature changes. Typically I begin by making many `"suggestions" to be decided on later.
If I enter one of these ideas ahead of other material already present in the song, inevitably the time signatures that were there before are altered. I understand that this happens because numbers must add up. Now, I wish there was a way to tell S1 "Don´t mess up time signatures after this marker. Whatever compensations need to be done, do them in front of this marker.