I was looking for an old message just now and I can't seem to find it. Come to think of it, I'm not sure I'm even searching the transcript for the right room!!
Can we get a transcript search mode that's not gated in scope to a single room?
This one has been on the roadmap for a while — it's been requested in chat before but it's good to have it officially here as a feature request.
Implementation is tied up with bringing transcript search into a pane on the main chat windows rather than having it's own page, details of which still need to be worked out.