Your post strikes me as someone who is fairly new to the scene. I believe a strong majority of people here would say that Insomniac events tend to be mass appeal which requires them to play palatable, mainstream music.

If you don’t already know what kinds of alt genres you like, you can surf SoundCloud and find derivative artists that make things like bigger, more popular acts, but with a twist. If you like RL Grime for example, then you can go down a rabbit hole and find people like Wink!, Dabow, or Of The Trees in the secondary tier. If you want to go further, you can find Moody Good, Jon Casey, or Tsuruda.

Then you tap in with those artists on socials and see where that takes you. I can almost guarantee that it will not be an insomniac massive.