HC-SR501 decrease effectiveness

Hello all! It has been a long time since I bothered you with a question, so here goes.

I recently purchased a cheap PIR sensor for a project. Not realizing how strong it really was, I planned my project around it and when it came time to test it, it works too good. The question here is, besides the dials to lower the sensitivity and removing the dome, is there a way to lower its effectiveness?

HC-SR501 is the scanner I purchased.

Attached is my project for for reference. The sensor sits inside the “door” roof entrance. The plan was to have the person wave their hand in front of the window, and a pen would come up. I am open for suggestions, because at this point, when I enter my office, a pen comes out. XD

I should mention, I am totally open to replacing the sensor for something different. Such as a HC-SR04 Ultrasonic sensor, if you believe it will work better. Even placing the sensor behind the device instead…