Especially when Reg is behind Cloudflare. Cloudflare make it as simple as ticking a box to enable IPv6.
You're half right. Enabling IPv6 on Cloudflare is indeed a flick of a button. Unfortunately there are still a few internal systems which wouldn't work when clients start sending them requests using an IPv6 address. In fact, we _had_ it enabled "for testing" on the old channelregister.co.uk site, and that showed us we had a lot of things to fix before we could enable it on thereg also.
We have a branch which purportedly fixes everything IPv6 related on our systems, and I'm now in a position to properly test it.