It is just a personal project.
If front wheel lifts high the suspension will not suffice.
The factory systems have access to several parameters.
I believe the factory and racing systems are mostly based on gyroscopes/IMU and also wheel speed which differs front/rear when the front wheel lifts.
I tried an Electronic Tilt Switch last year. But it was probably for slower or stationary objects like fork lifts and cranes. It was disturbed by bike acceleration. But this year I learned about Arduino and microcontrollers so the choice of sensors has widened.
I will probably use IMU instead, if ultrasound doesnt work.