The team is working on #2 (and has been for awhile). We will update as soon as we have more news.
ThanksAndy McAllister commented
really struggling with a Federation issue. We have set federation for the ONLY domain we want to communicate with; this is for security purposes. Sure enough, in the chat window, I can chat with internal resources, users from the federated domain and nobody anywhere else. All good.
BUT, if I schedule a Teams meeting, I can add a user from a none-federated domain as a recipient and they can not only accept the invite, but they can join (once admitted from lobby) and participate in chat, audio, video and sharing.
I don't want to allow invite of non-federated users and I certainly don't want them to participate.
Why are CHAT settings working as expected but MEETING settings allow federated users?
Am I missing something? Am I doing something wrong?