Hey folks,
Doesn't look like the forum is offered over IPv6 yet. The IPs are registered to AWS, and AWS has excellent IPv6 support, so it should be easy to enable. It'll get you one step closer to getting rid of the AWS IPv4 tax and improve performance for mobile users.
From the headers, the forum doesn't seem to be using CloudFront (which would make enabling IPv6 easier and save bandwidth costs too!).
If you can make this happen, it'd be noticed and appreciated. Thanks!