I’ve got a similar community with lots of subcommunities that meet regularly - although a little different as it many are within a larger organisation
You should already be able to achieve this, using categories (rather than tags) to control the access and silo’ing it as you need. But being able to use tags would increase the flexibility significantly.
You can continue to use the Discourse Calendar (and Event) for the ‘front end’ of events, and substitute in the Events Plugin 📆 features as you like. Your real world testing would be very helpful, and we can dig deeper in the Pavilion site:
(We are looking at federating topics like this one between meta.discourse.org and coop.pavilion.tech soon)