My advice would be to read the jumpseat pass of the airline you are riding on. It should be spelled out what to do, either stop by the cockpit or not. Horizon and Hawaiian both had policies to introduce yourself after the flight (Horizon) and only if asked to by the purser (Hawaiian).
That being said, I once jumped on Hawaiian and did as was instructed, I went straight to my assigned seat, and halfway to Honolulu the flight engineer came back and asked for my credentials. He seemed perturbed that I hadn't stopped by to say hi on my way in but I explained that I was doing what the jumpseat pass said. He didn't seem to know those instructions were on there, as I would guess many do not.