The heat seekers see the F-22 exhaust just fine without after burner. They can see the inlet too.
F-22 is a great plane, but you have to fight it like a F-22, that is to shoot your enemy before he sees you. If you wait, then you lose a big part of your advantage.
The unstable planes like Gripen or Typhoon have some advantages in close. F-22 drivers should know that, and avoid their advantages. Never give a sucker an even break.
I like the ability of the F22 to fire their AMRAAMS using the radar of a distant AWACS without ever turning their own radar on. The enemy won’t see it coming.