I would echo the thanks for looking out for your miners. I moved my 1Gh/s on to the new url...a bit surprised that this modest hashrate puts me in the "above average" crowd.
I would certainly help test the new proxy/code when it is ready. Again; thank you.
There is a bit of a manual selection involved in flagging miners for the private DNS. It's based on a few factors, the first of which was pure hash speed. Since then, more factors like account age, online time, and efficiency have been used to extend the private DNS to a larger number of miners.