Movement Tolerance for Spawn Per Unit Does Not Function

Motion tolerance for Spawn Per Unit does not affect the particle system. Even if the vaules are set very high.

Found in 4.18 CL# 3832480, 4.19 CL# 4033788, 4.20 CL# 4369336, 4.21 Preview 2 CL# 4472090, and 4.22 CL# 4491638

1. Open the Editor
2. Create a new particle system and add a Spawn Per Unit module
3. Enable motion in the viewport 
4. Select Spawn module and set the rate to 0
5. Select Spawn Per Unit module and set the constant to 1
6. Set Motion Tolerance to 1111

Results:
No change to particles spawning

Expected:
The motion tolerance set to a high value should prevent the spawning of particles