The average number of customers on a private jet is 2.5 people per flight.
What happen if the flight is full?
Well, it can happen that the VIP flight attendant will be offloaded to sell his/her seat to one of the customers.
This is not applicable with the jumpseat in the flight deck, but only with the seat located in the crew suite or crew rest area, which is identical to the seat in the cabin.
Well, if you have to stay on ground because the flight is full, you jump on an airline and you fly to destination to re-join the crew and the jet.
Who said this job is not dynamic?!?