I think...after studying all the various fixes, The easiest (for me anyway) is to simply buy a 3/4" wide piece of the UHMW plastic to fit the existing cut-out in the bottom of my door. (2) 6" long blocks at either end where the rollers are should work great and slide along the existing lower track lip..
UHMW Rectangular Bar | U.S. Plastic Corp.
I'll Route a rounded bead down the center to align and fit to my existing metal lower track and call it a day...No Muss, No fuss for <$10
With this approach I actually like that there will be some friction here to keep the door from rolling back and forth without being latched in the full open or full shut position all the time since this opening is side to side and I often like to partially open/shut the door..