Hey Martin,
I truly don't understand what the goal is here. Chris T. presented some valid concerns about http-01, tls-alpn-01, and dns-01. But I believe dns-persist-01 addresses these concerns. So why are we trying so hard to avoid ACME? If I knew what the concern was then I would try to help solve it.
This contribution didn't acknowledge the ALIII Authorization Token (AAT), so I will assume you consider CM and AAT validation separate functions for the same reason you consider CM and DV separate functions. Operating under this assumption, I have submitted a contribution asking several questions about how your proposal would work.
Sincerely,
Alec Fenichel
Chief Technology Officer