Help mapping ST device to harmony remote button

The harmony home companion is also available in white, or at least it used to be.

http://www.amazon.com/Logitech-Harmony-Home-Control-Devices/dp/B00N3RFC8W

That model (white or black) is the only one that has the special buttons for controlling home automation devices. All the other models just use the harmony activities.

As far as workarounds, try asking in the following thread. Those are the people using the official SmartThings integration, so they should have ideas.