Soft Contraint's Stiffness and Damping settings don't affect anything

The settings for "Stiffness" and "Damping" in the Soft Constraint setting for Physics Constraints doesn't seem to have an effect on anything.

Regression?: No
This also occurred in 4.14

1. Open the attached project
2. Press play and notice the behavior of the two assets
   Result: Both assets' physics constraints have the same behavior, despite widely different settings for Stiffness and Damping.
   Expected: Due to the difference in Stiffness and Damping, the two assets behave in different ways.