We have dropped plans for those features, because uptake of the multiplayer feature is lower than we expected. Before development we ran polls asking what features people wanted the most, and multiplayer always won by a significant majority. But then when we released the feature it seems loads of people voted for it but then never used it. I think this is a mix of the fact multiplayer games are hard to design, even with a tool like C2 doing much of the heavily lifting, and also possibly partly due to WebRTC still not being widely supported yet.
Anyway since those are difficult and time-consuming features to develop and there is still only a small audience developing multiplayer games, it doesn't seem worth investing in to for the time being. I'd recommend developing the features yourself with your own serverside and possibly your own JS plugin.