Nope this time is not the same as usual, is based on Vor TRK before it was HDG . I mean you can follow the internal Flight plan but you can't Track active HDG.
What INS is doing is to change the HDG to follow the route, so if you have active HDG there is no problem, even VasFMC do the same.
But here we can't do much as long as we do some sort of machinery setup in FSUIPC but is so annoying.
Why this method if it doesn't want to add Sperry 177 or CDU at list it should give as the ability to use external addon like ISG or what ever.

This is something that has to be request and really hope to change soon.
The hardware doesn't work with this situation I can't change HDG at all.