The Jedi and Sith with a Flood Spore part is actually a great visual for me. The Force is not Universal. It is, as far as we know, confined entirely to the inhabitants of the main Galaxy. Because of this, the Flood would be invisible in terms of the Force. This would probably make infection for a Force-User even more likely. This all assumes we are referring to all SW information, including non-canon. There's not really anything to be said otherwise.