I didn't, no -- but I'll be sure to ask when I chat with them next. I'm bound to think of a few more questions between now and April!
Yeah -- ISPs in general have a bit of a "tomorrow, forever" attitude to IPv6 (I'm looking at you, Vodafone). But what gives me a little hope is that a) this quite a young ISP, and b) the support person handled my technical queries very well. Didn't miss a beat over my CGNAT queries, and seemed very knowledgeable. His full reply re: IPv6 was that it was running within their network already, and that they were in the process of testing the configuration roll-out to their end-user equipment. Which at the very least, sounds feasible.