most of the time, when translating a message with a picture included or a screenshot. Translation will fail and message will not be translated even how many times you try.
better if Teams has this feature on the Chat tab so the sender will know if the recipient has already seen the messages that he/she sent.
The team is working on #2 (and has been for awhile). We will update as soon as we have more news.
Is the federation feature already working to chat to another user from a different domain?
We need to collaborate/chat to other users of our company that has a different domain name and having a different O365 subscription (not under our tenant).