XP30 owners--and a pretty large number of them at that--have from the very outset been well represented on the original JV/XP mailing list (see lilchips.com for details). In fact, I *left* that list because after a while the owners of the older series had largely figured out their instruments, and the newer postings were so often from new XP30 owners. That the XP30 has certain expansion boards built-in shouldn't affect interchange between owners of the various instruments any more than it affects owners with the same (or different) boards installed on the earlier series.
It sounds as if you're focusing largely on not being able to find patches--but in that sense, even earlier series owners don't exchange all *that* many patches. There are already so many available. For example, have you already downloaded and auditioned the four or five banks or preset patches from the older JV1000? That's a lot of patches in itself.
What happened on that list was basically that people struggled for a couple of years to get to know the instruments, exchanged some patches, posted some patch banks, learned how to program and tweak patches, and went about making music. When I left the group, most of the questions involved interfacing the XP30 (or earlier instruments) with various computer setups.
There are *so* many patches available for these instruments, and *so* many options for tweaking them, I think people generally find what they want, program presets or patches they find on the net, or just tweak presets (as I generally do; I'm not really a programmer) for their music. Most of that kind of thing (individual patches tweaked for a certain song) never gets posted or uploaded anywhere. The thinking is probably: Why bring sand to the beach?
I have never expected an infinite number of patches to be availabe for *any* instrument; there is already so much exchange and so many patches available.