My team was observing strange drifting behavior having to do with the slew rate limiter when coasting to a stop. The issue is that when a 0-velocity target is added to the slew rate limiter, a default angle of 0-degrees is assumed which results in the direction of travel getting smoothed across a range of angles from whatever initial angle existed back to 0 degrees - creating a curved trajectory.

The video shows a simulation of a non rate-limited swerve target, the current rate limiting implementation (yellow) and my new implementation (green).

Finally, it should be noted that the slew rate constants now have physical units (acceleration) but I have not renamed them - this can be changed if deemed necessary.