I 485 denied prior to j1 recommendation?

I would not do a motion to reopen. The denied application was not approvable when filed. Waiting for final approval would be the safest approach, but there is guidance that USCIS can accept an I-485 after recommendation from the DOS, even when final USCIS has not yet approved the waiver. Not knowing about your case, though, I cannot say whether or not your application is approvable even with the DOS recommendation.