I'm upgrading my rear sub frame chassis to a gen 3 I have a 22mm heavy duty sway bar on the the car already with coilover. Is it better to put the standard sway bar back in for the track? Or take off and have none?

Upgraded sway bar :) keep them in imo.
Where did you get luck to source a gen 3 sub frame?

I have two sdubs have a late build 92 that all so  has gen3 rear sub frame, but I bent my Gen 1 sub frame in the other sdub at the MTC16 and Fast Eddie was able get me two sub frame for free in Sydney. That where the luck came from.

I assume you mean the front sway bar is 22 mm.  Certainly don't need a big heavy one in the rear.  Either the original 18mm. or none would be my guess. Really gets back to front and rear spring rates, front sway bar stiffness, tightness of your LSD.  Driving style etc.   Maybe get everything else feeling right without a rear bar then try on track with the softest rear bar.