H1B approved, not stamped yet. Can I apply later under cap-exempt category ?

Hello experts,

I read conflicting statements about my case. My visa is supposed to start the 1st of October 2016 and for personal reasons I have to go back in my home country for a few months. I was wondering if I could leave the US before October 1st and then apply under cap-exempt later ( either the same company or another one ).

Basically, what are the requirements to stay under the cap-exempt with my H1B ? Can I leave before the 1st of October or should I leave after ?

Thank you,

IMO, the fact that your petition has already been approved qualifies for cap-exempt petition in future irrespective of when you leave US.

I know of cases where the applicant was always outside US even after H-1 got approved and was still eligible for cap-exempt petition.