That setup is good, but not great imo; purely because setting the castor in situ should be infinitely adjustable (like say a track rod is).
When the car's on a ramp being tracked up & castor set etc, I wouldn't want to be limited to 180° turns on a bearing that'll only get you 'close enough' N/S to O/S equal castor, having to jack the car up each time unbolting everything to rotate the next best guess each side at a time; it's just not practical at your local alignment place.
Don't get me wrong the quality of the fabrication looks perfect; just the design's not quite there imo.