Introducing UnreliableRemoteEvents

Does Roblox even use TCP at all (aside from HTTP requests)? I was under the impression they used a fork of RakNet which uses UDP only.

Are game events processed between an intermediary server between the user and whatever server receives the information (Like a triangle, host > server > server2 > host), or is processing and forwarding done on the same server? And is there any documentation on the infra for Roblox?

Iā€™m not familiar with RakNet but UDP is definitely the primary road of communication to hosts.