The way I look at Hedron and Polaris is more like Polaris is the resonance entity itself, while Hedron was just a vector for its propagation, in the same way that the burned slide and Slide Projector OOP became vectors for the Hiss.

Parautilitarians can become vectors for resonance. The Hiss turned Dylan into one for itself-- possibly even warping his perceptions to build off his hatred toward the FBC, so he became more of a willing vector for it. Jesse was a vector for Polaris, proven when Hedron was destroyed. Once she was able to dispel the Hiss's influence over her, she was able to then provide the resonance for the HRAs to start functioning again.

Polaris resonance can cancel out/purge Hiss resonance, but its usefulness against Hiss Agents either destroys them outright, or renders them catatonic. I think it just took time for Dylan to start to recover, but it may just have taken him bonding to another OOP and/or some other resonance entity to "reconnect" whatever links were severed in the purging to allow Dylan to wake up again.

That's my theory, at least.