It will automatically kick off the sync, and rebuild, so you don't have to do anything but it will take a bit to populate (but will almost immediately start the streaming)

So I could remove the inbox relays from my list except this and it'll serve up content from all my follows? And then I can maintain my own personal relay as a singular outbox relay, in theory? Sorry if the questions are a bit nooby I'm just trying to work my head around how it's all working.