Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
I would like to find a way to quickly add new scouts to invite/RSVP lists on previously scheduled events all at once so that I don’t have to go back and update the entire schedule to make sure they get notified and marked for attendance.
You can do something like this with the Feature Assistant Extension for Firefox and Chrome. There is not a native way to do it in Scoutbook at this time.