Any experience with how this works on the Teams mobile app i.e. changing to a guest account when trying to join a meeting? And if someone invites you to join from that meeting – then you get to bypass the lobby? But if there are other restrictions i.e. video, microphone then you would need to leave the meeting, change hats, and rejoin?

I do like one security aspect since a guest user may have a lower security in their home tenant but as a guest they could be forced into an MFA check.