You can't aspect on that ... if you have 1 million users and every user upload 1 mb (photo) you have an issue from start
)) because you must have 1Tb hdd .. and i don't count the things you can do on the community (likes, following, conversations and other stuff who are stored in database ... another space consumption), the cms and the list can continue...this is insane
)) ... now, if you let the user uploading 500 photo (on profile, group and page and every user can make only one group and page) and a photo has an average of 50 kb, one user can consume like 25 mb per profile, group and page ( let's say an average of 50 mb per user) ... you must have 50 Tb hbb ... This is the first thing you must think and you don't need to know much about the connections made to the server, the consumption of the resources , the bandwidth for upload and so on ...
This can be solved by displaying a minimum requirements and an option on back-end to switch on this kind of behavior ... with a big warning ... don't switch this on if you don't have at least a VPS with x CPU cores and x Gb RAM
So, you will improve ConverseKit to behave like a real chat window?