Reversing direction causes motors to jerk

Here are my files.

Is it normal to have no joint definitions?

DIRSETUP = 100
DIRHOLD = 600
STEPLEN = 2000
STEPSPACE = 1000

Have you tried setting these to 5000

I just tried 5000 for all 4 values. No change,

Your sample files have backlash enabled. I would definitely set this to 0 while trying other settings (as backlash compensation is guaranteed to make a jerk when reversing)

For timing, I would use
DIRSETUP = 20000
DIRHOLD = 20000
STEPLEN = 5000
STEPSPACE = 5000

As this will work with almost any drive (up to 100 KHz)
just like leaving backlash=0, leave the step/dir timing at this value
until you resolve the jerk-on-reverse issue

I turned off backlash and used your settings PCW. Still no change, but I'll run with this configuration until I get it sorted out. Thanks.

You could try the step and dir on the minus posts.

That's how my geckos are wired

I just tried moving the pins to the minus posts. It reversed the direction of the motors, but otherwise no change.

Note, just like the backlash and timings, using the minus outputs is necessary
even if it does not impact the issue you have...

What is your micro step set to?