Update: I just took the dll, without installing it, and put it in my VSTs folder, and rescanned VSTs. Then Triangle II showed up in my instruments. I was able to create a simple instrument track for it, but....
All other instrument tracks got mysteriously routed to the Triangle track. Things went downhill from there, e.g. X1 stopped outputting any audio, etc...
I'm about to give up on Triangle II, unless someone can explain how I can get it running in X1.
Even though I have a large arsenal of synths, including Rapture, z3ta, Pentagon, Zebra, Ace, I still miss having Triangle. It's unique.