Unless it's a company check captain why allow any others access to the jump seat?
Whether it's another pilot, a CASA amateur pretending to be a professional pilot, a flight attendant (God help us!) or a company employee, they're all a pain in the ass in the cockpit!
I got rid of the pax years before the 9/11 thingy took off.
Best thing I ever did!
Keep them all out suits me fine.