Haven't I been saying ALL ALONG that a zero fret will be the same for intonation as a perfectly cut normal nut, difference in tone being a separate issue?
<shrug>
If you're looking for more of an argument, Perry, you won't find it here.
However, the assumption that they'd be used by more manufacturers if they were great is a fallacy in logic called, "ad populem" which means that you are using other people's preferences as an argument. People do it every day, but that doesn't make it any less of a flawed argument.
It's not like I never looked into these things, and part of the problem with my guitar's progress is that I research TOO MUCH. Technicians, Buzz Feitin's site, Koch's book, a different forum, have all supported the idea of zero fret as a good one. All I ever said was, "don't overlook it because of elitism", which a lot of people seem willing to do.
Greg