There's not much participation in N30 in the Pacific Northwest. The only time I flew in it was because I'd just gotten through physical therapy for my shoulder, I could fly again, and I wanted a trophy to show to my therapist. I got first, last, and everything in between because I was the only one flying it.
There's just not a great deal of difference between today's designs and most of the designs of 1992. I'm not enough of a historian to quote any others, but the first Impact article came out in 1991, and while there have been many detail changes to the design since, you could build one from the 1991 plans and if you didn't make it into the top 20 at the Nationals, it would be because your piloting, not the plane, was holding you back.
The one caveat that I will mention to the above statement is that among some top electric fliers (Paul Walker, Chris Cox and Alan Resinger in the Pacific Northwest, plus some members of the PNW Junior Varsity) the trend has been to fuselages with a much larger cross-section, made with monocoque or semi-monocoque all-molded construction. The principle is that you can get the same rigidity with less material if you use a bigger fuselage, and you're not held back with needing more local strength to overcome engine vibration. But right now it's only the top pilots that are going in that direction, and it seems to be the sort of thing that only shows up when you're flying close to perfectly anyway.