Answering a turn, and asking your own question

Every answer starts from something: a line of theirs you lifted off the transcript, or a question you typed. ⌘↩ sends, and ⌘↑ and ⌘↓ walk back through what it has already answered.

The shortcuts are registered with the operating system for the length of the call, which is why they fire with the meeting app in front and no window has to come forward. When the call ends they go back to the system — and a paused call is still a call.