It would be good if a demo board A could be cloned by another user to B, and when A adds moves they automatically get added to the game tree of B, but B retains control of what position is being shown (if B has already shown the game move the trees need to be merged). This is useful when A is a broadcast online of a real life tournament game, and B is the commentator showing variations.
Yesterday I did the commendatory of the British Go Championship, and we did both the game relay and commentary on KGS. The presence of this feature on KGS and lack on OGS was one of the key reasons for choosing KGS. Another is KGS has in-built audio commentary, but as we are thinking of doing video streaming to twitch next year this becomes less relevant. I know that some of the EGF professionals like Ali Jabarin have mentioned this lack of demo clone was also why they broadcast and commented some games on KGS rather than OGS, with video streaming to twitch. But there are some advantages to OGS, such as an easily shareable URL to the game with no client install needed, and a nice way for users to share variations. If OGS added the demo clone feature, that would help us to pick OGS next time.
Also what is the OGS policy on previously banned users making reviews which are then promoted as events (on KGS your game goes to the top of the game list, on OGS with those little pop up notifications)? A KGS admin refused to promote my review because I was on a blocklist, presumably as I have been banned from KGS in the distant past (last time over 10 years ago iirc). I have also been banned from OGS. Would this be a problem here?
N.B. This feature was previously requested at Feature Request: Clone/Review A Demo Board For Game Relays but that thread was auto-closed so I couldn’t comment there.