F) They added a third-party verification so that Russian authorities can add an "A+" mark to channels who are complying with the new law and are registered (social network channels/blogs with more than 10K subscribers must be registered with the government now and have the owner identified).
I thought it worked the same as Whatsapp, whereby there's a sort of backdoor connection to the app running on your phone to send messages.
However, after doing a smidge more research it seems like somehow Signal is sharing it's key with the desktop app and only syncing history of messages directly: https://news.ycombinator.com/item?id=15596980
I'm not 100% sure how it works as the server is fake-open-source and not actual open-source.
I've tried to use Matrix a few times and eventually end up leaving. The idea is good, but it's just missing so many nice features that it kinda isn't worth the pain. Features that Telegram just keeps dropping like candy.
Just got inspired to try it again after not touching it for at least a year. I login with Element and am hit with a notification to verify my session with another device to access my encrypted history. I have no other sessions. Does this mean I've irrevocably lost access to said data? This is unacceptable if I'm to use this service regularly; I'd rather have encryption off by default so I opt into the potential loss of data, instead of having to remember to opt out. The only really nice thing so far compared to Telegram is my account still exists with the chats I'd joined, while Telegram allows a year maximum inactivity before it totally deletes an account.