It's not really a club, per se, but a guy named Mark Watson models modules in Free-moN. He live in Lincoln NE, and I know he has connected his own modules to another from Free-moNorthernCO (Nick Husen).
Free-moN uses this (pretty loose) standard for module interconnections:
http://free-mon.net/standard.html
Free-moN groups meet an connect at various locations throughout the west on a semi-regular or one-off basis. I believe there is a monster meet too in Evanston WY every few years at was (the last time) the former UP machine shop--next meet in 2024 I gather.
[Why this doesn't happen several times a year is, so far, a mystery to me]
Some video here:
As it happens, the opening shot is Mark's triple way connecting module. I really like his grasswork, and the dead end abondoned track (which runs into the tree) is another nice touch.
Standard height for Free-moN modules is 50," which suits me much more than does the N-Trak height. Free-moN is also a single track, rather than triple track connection. That, too, suits me. FWIW.