I know this thread is pretty old, so I’ll consider myself lucky if it revives. I am in a similar position - I got 20” rims from the first gen and want to use them on my second gen. OP - did you find a set of lug nuts that work?
Unfortunately the lug nuts from the second gen won’t work with these rims. The studs don’t stick out as far with the first gen rims, so they can’t get enough thread contact. I’ve gone to a couple of tire places trying to find lug nuts that will fit, but apparently they don’t have any that would.