It is 2016 now. Comcast generally has IPv6 enabled on their network, and I'm sure several other ISPs do now as well. There should be a reasonable expectation for IPv6 usability at home. That should allow for a good segment of the public to test this functionality. I would hope some or all of the Devs would have access as well. The barrier to IPv6 accessibility has diminished greatly. There really isn't an excuse for not developing this feature other then it isn't deemed a priority. Though that shouldn't be the case either, We have depleted IPv4, and every day the need grows for IPv6 adoption.
In general, I would be willing to help with the development but I have a couple limitations. I currently have limited internet access and will not be truly available for the next couple months. Additionally, I'm not a coder, but I would be willing to run test configurations when I am able to bring up a network environment.
Granted, I am speaking from a USA perspective. As an open source project I would think that development would take place from many points on the globe and as such I would hope that some of the development staff was in the USA.