UPDATE!
So, I started from scratch and uninstalled everything related to iConnect from my PC, including all of the drivers, iConfig, etc. Then, I just simply connected the ICM2+.
Voila!
S1 is seeing it as a MIDI interface.
However, iConfig is a pain, as it gives off a communication error and restarts itself every 30 seconds-1 minute. Luckily, I managed to get a CC#123 filter on both DIN's. (The only thing I'm using the ICM2+ for is the RD-1000, so why not?)
Played the RD through S1 using Falcon (one of the KeySuite pianos), and checked the MIDI monitor in S1, and all is well--no more CC#123!
Now, I've read on other various forums that the ICM2+ is a bit flaky, so we'll see how long it lasts.