As mentioned in my Reddit post:

https://www.reddit.com/r/NintendoSwitch/comments/8u3dri/its_been_almost_a_week_with_the_new_minecraft/

Since I mentioned invites, I click on invite player from my Win10 version and pick the Xbox id for my Switch. On my Switch you get a quick popup that lasts about 2 seconds tops, and tells you that you have an invite and press the - button to accept. That's fine if you are the Flash(tm), because if you miss the invite, which I have done even knowing it was coming, there doesn't seem to be a way to pull it back up. On the Xbox you can go to your messages and click on it, or on the Win10 machine click on the messages and click on it. On the Switch, miss your two second window and it's gone.