Okay, after fruitless efforts to find a way to get ST and Indigo talking, I gave up. (Indigo is a Mac-based home automation software package.) I bought a Z-Stick.
In short order, I had Indigo set up, communicating through the Z-Stick, and working. The first thing I added was the CT100 thermostat that ST refused to find. Setup in Indigo took about five minutes. Sweet. Same with Hue; after removing from ST, setup on Indigo was quick and painless.
Now that I have what I was after all along, a computer-based HA control center, here’s my question: Is there gonna be a way to have ST be useful? For example, can I use HAM Bridge to construct an Indigo trigger based on input from a ST multisensor? Or am I better off selling my ST hub and going exclusively Z-Wave through Indigo?