In your letter dated Wed, 26 Oct 2016 15:54:52 +0200 you wrote:
So, how about we go the other way. We want IPv6 to be taken more seriously. What about if we change the algorithm the other way over time: give IPv6 more and more of a head start. That way IPv6 stability and performance become more important over time, without causing brokenness. Something like:
HE head start = 300 + (months after 2017-01-01) * 30
That would provide some incentive to make sure that IPv6 is properly deployed and managed.
Looking at this from an operating system perspective... As an experiment I implemented a fully dynamic version of happy eyeball in my toy-os. It keeps long term statistics about the performance of v4 and v6 and will give v6 a small head start to add a small positive preference to v6. But if IPv4 is really much better than IPv6, it will not bother with IPv6 at all. I don't any reason why any system code would implement what you suggest. Basically, in a situation where IPv6 is broken, your suggestion would make the user experience worse and worse. For the user, there would be a simple way out of this mess, just disable IPv6 and performance is back to normal. My suggestion: try to get IPv6 to be 80% or more (at least make sure that IPv6 from content providers is almost universal) and then for eyeball networks to stop investing in IPv4. When IPv6 support is the default, people will notice that some sites have bad performance and that may be because their IPv6 support is just not there.