Make survivor not hear the Chase Music after starting a chase with an Undetectable killer
The point of the Undetectable status effect is for the killer to not be seen by any survivor when he approaches then, but when he gets the first hit, the survivor runs away and the chase music starts for the survivor, even tho the killer is still Undetectable. The chase music completely counters the Undetectable that the killer have, as the survivor already know he is after him, so it would be a really nice idea to remove the chase music for survivors while the killer is Undetectable.
For instance, if a survivor is being chased by a Tier 1 Myers, and the survivor goes behind a wall in a tile, the survivor can easily assume that he is still being chased since the chase music is still going, so he would be more careful. But if there was no chase music, the survivor would never know if the killer left them, or is just hiding, waiting for the survivor to left that tile, which would be way more scarier.
This could even add a new depth of scariness to the game, as the Undetectable status would really be "Undetectable". Like, imagine being chased by an Undetectable killer, and hear no music at all, how creepy would that be?