Yes, that may be challenging. But you can always query PeripheralVisionAngleDegrees like I did above and then simply run your own custom checks afterwards as workaround.
AI Perception is kind of an abandonware so I feel like we’re all scraping the barrel with its capabilities.
edit: Also look into CanBeSeenFrom function. You can add your additional vertical vision angle logic in there on top of usual linetrace without overriding SightSense.