In Rejoice for You Are True, when you go to the Alabaster Court, how would the scanners looking for psykers react to an untouchable? Would they call him a heretic or untrue?

In the final episode of the trilogy, would the ghosts on the Black Ship be able to affect an untouchable and his gear if the party is found out as Inquisition and the ghosts attack? Would they attack/run away from the psychic hole he is?

I don't think that untouchable would regester from the "harmon meter" since it measures physic talent. Being untouchable you are lacking anything physic you are just anthema to the physic realm. I bet that the tech being as old as it is may be able to be re worked to detech such a thing...but I don't know of anyone in that adventure that would think to do something like that.

as for on the blackship...the warp ghosts can attempt to attack the untouchable...but remember being untouchable you can not directly be harmed by physic powers..nor possesion. As to actual attacks I don't really know I would think not since they are warp ghosts. I would say that it will come down to GM discresion.