That's part of what I'm having trouble understanding, because it sounds like that's exactly what's being proposed, except also using said person to somehow cast Illusion? It just doesn't make sense. Anything that needs an operator doesn't make sense because it runs into the same issue of communicating things to the runesmith, and if it were as simple as casting an illusion, we would have done that. To be honest, I have no clue how a Seviroscope would even work, but this probably isn't it. Hell, if I didn't have faith that Boney wouldn't give us such a massive prompt and mystery as Bok while making him impossible to figure out, I would probably give up on the whole thing.
That or I am just tired and having brain difficulties at the moment. One or the other.