It could be useful to have a button to freeze the “Follow playhead during playback” feature in one window (or tab)
Imagine the situation, where I am correcting something from the first and the last flow. For that, I open one flow in one tab and the other flow in the other, this way I can easily copy content from one flow to the other. However, because pressing P will put whatever is playing in focus in both windows (or tabs), I must remember not to use audio feedback. However, for those situations, the audio feedback is useful as I can easily detect a mistake either while entering the music, or when pressing play.
If that is too difficult to implement, the alternative, at least the ability to add a keyboard shortcut to the Follow playhead during playback, would allow to temporarily deactivate it, press the shortcut to return to the previous state.
Another workflow where this is helpful is if you have one flow with information that you want to keep always on the screen during a piece. For example, sometimes when composing I create a flow just for some notes on the range, Rhymic patterns, melodic patterns that I want to use (like the ideas feature of Sibelius).