I’d like to suggest that the board owner has the ability to control if the music is playing for everyone on the board once the timer has been started.
I usually run workshops with google meet, start a timer with music. At the 2 min and 1 min milestone - I want to be able to call out people, share thoughts, reinforce reminders and realise that even though I have muted my music - the participants might be hearing it from their Miro board.