Boards like Avalon clones are already at the edge of obsolescence.
KnC has no trouble with conventional, "cheap, simple, reliable and well characterized thermal solutions," lol.
While water cooling might have been bleeding edge in the 90s, it's consumer-level commonplace today.
Ken never built any miners, including Avalon clones.  The fact that he was *going* to build them gives him exactly zero experience with any design, obsolescent or otherwise.
It pays to know the basics about your subject before bringing up "watts per meter" and brandishing absurdities like "100W out of four half inch squares."