Answers
Can you schedule a message to send later?
Some platforms support it natively, others not at all. It is worth knowing that a scheduled message on a screened platform is checked when it sends rather than when it is written.
Scheduling is most useful across time zones and for anything that would otherwise arrive at three in the morning. Its risk is sending something you have stopped meaning by the time it goes.
On a platform with pre-send screening, the check happens at delivery, so a scheduled message can still be refused after it was composed.
A simpler alternative that works everywhere is writing the message and leaving it as a draft.