When passing a vehicle marked with the visible blue plate at the front and rear and with the hazard warning lights on, are you always obliged to stop whenever a disabled person is getting in or out of the vehicle?

No, because the regulations do not impose an absolute obligation to stop the vehicle in every such situation. When passing a vehicle transporting a disabled person, the driver is required to exercise special caution and to stop, but only "if necessary", to ensure safety. The obligation to stop is therefore not unconditional and depends on the specific situation on the road.