Oops, I meant to say 91K
Oops,
You are right, Dera. I stand corrected as I remember Mountain Air, Key Lime, and other Part 135's etc. were on our CASS list.
Unfortunately, Netjets is 91K and cannot really reciprocate. We didn't care about this and regularly had Netjets, Flexjet, XOJET, Flight Options, etc. pilots on our flight attendant jumpseats outside the bulletproof cockpit door. We were just happy to help our fellow pilots, and it's funny that a lot of us ended up here in Part 135 and 91K when the music stopped.
In the early 2000's, I invited 2 Netjets pilots trying to start a reciprocal jumpseat program as my guests at the Annual Jumpseat Conference. I know that they were trying to get Netjets to publish the empty legs that they were repositioning between revenue flights, but I don't think that it went anywhere.
I don't know the Atlas B767 and B747 cockpit configurations, but if there is a secure cockpit door, I believe that you can carry non-CASS jumpseaters OUTSIDE the cockpit. I would be tearfully happy to see Netjets and other 91K pilots able to jumpseat on Atlas and elsewhere.