Another thing I did with the aforementioned was to add TCPIP (a later version). It meant you could launch a VI and then communicate with it via strings sent from Test stand - even on remote machines. The wrapper was only slightly more complex than the pure launcher but it meant you could configure the devices on-the-fly, abort or reset devices and query state information with simple strings from Test Stand (I used SCPI-like commands).
Anyway. I diverge.
You've probably guessed by now that the choice you had was to have an instance per device which you control and sequence from TS, which is what I was describing, or an application that does it and reports back to TS, which is what you are designing. The others have given you options for the latter and I was just giving you a method for the former.