I know they don't like third party implementations because then if you need to make a protocol change you'd have to wait 30 years for everyone else to update their clients. But if you're already requiring a single client that it makes it easier to do decentralized messaging for exactly the same reason.
Another option that works pretty well is to do both. So try decentralized (DHT / direct connection) first and fallback to a central server if that doesn't work. Then you're up as long as either one of them is working. And there is a lot less load on your central servers.
I know they don't like third party implementations because then if you need to make a protocol change you'd have to wait 30 years for everyone else to update their clients. But if you're already requiring a single client that it makes it easier to do decentralized messaging for exactly the same reason.
Another option that works pretty well is to do both. So try decentralized (DHT / direct connection) first and fallback to a central server if that doesn't work. Then you're up as long as either one of them is working. And there is a lot less load on your central servers.