Ignore the service itself. It's just an example of an implementation of the concept. You can implement it using proxies instead of using AWS' Edges (which is basically what AWS is also doing).
Like I said, spin up an Azure or AWS environment (wherever you have free credits) and test if for yourself. I tested it with the L2jBrasil folks when I originally created it and that's where my results come from.
Now about the "torture testing". I define torture test as 1 million concurrent connections with maybe 10m requests per second. Has it been torture tested this way? Nah, but it's perfectly stable with at least 500 L2 concurrent connections without any signs of degradation. Keep in mind that traffic is also segregated. It's perfectly stable and perfectly fine to use based on no compaints from at least 20 servers that I personally know that are using it.
And at the end of the day you don't even have to use the service itself. Simply gets a VPS and configure it as a proxy. You can still use the Java part. You just lose some features but gain all the benefits of the concept.