So… it appears that the Lyric T6 Pro Wi-Fi will not connect to ST.
It is not showing up in the list of available items after I authorize SmathThings access to Honeywell services.
Support says it only works with this: https://support.smartthings.com/hc/en-us/articles/205813563-Honeywell-Lyric-Thermostat.
Anybody have any ideas?