Is it true that you should not start the after landing checklist until the aircraft is clear of the duty runway?

The statement is true because the after landing checklist should be performed only after the aircraft has safely exited the duty runway. This practice enhances safety by ensuring that the pilot can focus entirely on taxiing the aircraft without the distraction of checklist items. Once the aircraft is clear of the runway, the pilot can then attend to the necessary tasks without the risks associated with navigating while still on a runway where other aircraft may be taking off or landing. This procedure helps to maintain situational awareness and ensures that all primary responsibilities related to aircraft control and safe operation remain the priority until the aircraft is in a position where it is not in immediate conflict with other operations on the runway.