As you have noted, you do not actually need a STB (PUC) setup in the configuration other than to add V.AUX & DTV/SAT etc.
The only reason to have the correct STB is after it has been selected where it has "Guide" and other functions, but these can be added manually if your STB does not appear in the list.
So, the bottomline is, if your STB is not in the list, it does not stop you controlling the connected STB, it just means you may not have all the sub-menu keys available.