With REST I could probably figure something out, but web sockets are a bit confusing to me. Sure I could use node, but just to hide my own key, I'd need a separate VPS server + additional SSL + time to code node + time to modify cloud code.
How much more practical would it be to create an extension to the JS SDK to just [optionally] initialize with PHP and continue with JS? Everyone has PHP, you don't need a VPS, and could be generically coded to support the existing JS SDK.
Thanks for the feature request, I'll pass this onto the dev team for review.