/cumg/ was a regular thread on 4chan's /g/. It was extremely active, and to this day still is. Usually hitting or coming close to thread caps. It is probably one of the most active generals on the board. The jannies actively have been trying to ban people for any little thing in the general, even if they have not broken the rules.
It is highly preferred to talk on the FChannel general (instead of EndChan, and instead of 4chan), due to FChannel's federated nature. It is a hope that we can be more active there now instead of 4chan, however feel free to also continue posting on 4chan/g/ until the moderators ban you for some stupid shit if you please.
We also have this Endchan board has been created so we have our own place to talk. https://endchan.net/cumg/
A general was started on 2chen which is a new meguca-based imageboard. https://2chen.moe/tech/1353679