I've been playing Demogorgon for quite a while now, and I got to say I'm extremely impressed with his design. He really is extremely fun to play as. The devs did an amazing job with him.
However, I do think he needs a small nerf. I just think that when you put traps on all the gens, it's a bit too much that he always knows on what gens survivors are working on and that he can teleport around the map so frequently.
I would suggest to either increase the cooldown of the teleport from 14 to 20 seconds, or increase the radius of the portals at which survivors can be detected via killer instinct, but make it so that survivors that are working on gens or cleansing totems can not be detected with killer instinct. Good killer players are anyways able to often predict correctly on what gens survivors are wroking on. Having an unlimited Surveillance and Discordance is a bit much in my opinion.
This is just my opinion. If you disagree, that's fine. No need to get offensive though. From my personal experience though, I do feel like his portals will need to be nerfed in one of those two ways.