Heh, based on my initial research I thought "Tange Chromo" referred to a specific grade of their chromoly tubing. I think the problem was that some Korean resources (where I'm building this) refer to it as something like "tange chromo chromoly". Anyway, now I see that Chromo is not actually one of their chromoly grades, so my post was even less informative on tubing type than I thought!

The reason I came here before meeting the builder is that cultural and language differences can make this kind of consultation challenging at best and I wanted to go into the meeting with a more informed opinion. I'm starting to get that, as a growing consensus suggests that 1) lug quality per se doesn't matter and 2) most riders won't notice the difference when upgrading from good basic tubing.

I don't want to highjack this thread, but if others still want to comment I'd love to hear from you at the Framebuilders post I started on TejanoTrackie's advice.

Thanks y'all!