It's a bit of a long one, so bear with me.

On my second playthrough of the game, I realized that I don't actually know where the slide projector is being kept now. So I went looking back in Dimensional Research, maybe Jesse put it back there. Didn't find it there (and a quick google search showed me that the slide projector isn't in any area of the map that we're able to visit), but I did hear an interesting bit of dialogue when I swung by the Hedron Chamber on my way there.

In between fighting off those floating telekinetic Hiss and those invisible screamy ones, Jesse questioned why Hedron only brought her to the Bureau, to Dylan, now of all times. I wish I'd recorded it (I'm sure we can find it online somewhere) but basically, she came to the conclusion that Polaris or Hedron only called her to the Bureau when it did because all it "wants" is for her to fight the Hiss.

It never wanted Jesse to save Dylan, and from an in-game file found in the P6 room in Prime Candidate, we know that Dylan had a moment of outburst, lashing out at somebody even though no one was there with him. He said something like, "I don't care about you anymore, or her! Leave me alone, bitch!" I'm pretty sure this outburst was directed towards Polaris, or Hedron, reaching out to him.

I think the reason Polaris "left" Jesse for so long was because all it wanted was for somebody capable to fight the Hiss, and Dylan was already there, at the Bureau, being groomed into the next Director. And the only reason it reached out to Jesse again was because Dylan had given himself up to the Hiss. He wasn't a viable candidate anymore, so it was time for plan B: Jesse.

Throughout the game, Jesse believes Polaris to be some kind of guardian angel figure, which it was in the most technical sense. It protected her, but only because it needed her to fight the Hiss. Maybe instead of Polaris or Hedron being some inherently benevolent force, maybe its nature is simply...contradictory (?) to the existence of the Hiss. Like how water puts out fire, but in this case both the water and the fire are sentient, interdimensional, resonant-based lifeforms.

Maybe?

tldr: Polaris only ever wanted to fight the Hiss. It never cared about saving Dylan, or anyone else. It just wanted the Hiss gone. It tried to get Dylan to do that, which failed, so it went back to Jesse. So basically instead of assigning Hedron (and the Hiss by extension) human attributes such as good and evil, guiding and corrupting, they're just two alien lifeforms whose very nature is to be at odds with each other. Maybe?