Generally speaking, most guests don't have motion sickness issues with Millennium Falcon: Smuggler's Run. I think it helps that you have to look away from the screen and focus on actual tasks. Also, the whole ride experience is smoother and a lot less jittery than Star Tours: The Adventures Continue.

Millennium Falcon: Smugglers Run is a motion simulator attraction at Disney's Hollywood Studios and Disneyland, and while it is generally smoother than the classic Star Tours, it can still trigger motion sickness in susceptible guests. The ride utilizes a 4K digital projection system and a cockpit that tilts and jars in synchronization with the visuals. Because it lacks 3D glasses, some find it easier to handle than other simulators, but the "enclosed" nature of the cockpit means there is no external stationary point of reference. Interestingly, your specific "role" can affect how you feel: Pilots often report less nausea because they are actively controlling the motion, providing a sense of agency that helps the brain sync what it sees with what the body feels. Conversely, Engineers and Gunners in the back must often look sideways at their control panels while the ship is pitching, which can cause disorientation. If you are prone to motion sickness, sitting in the pilot's seat or focusing strictly on the central screen while keeping your head still is often the best strategy to enjoy the jump to lightspeed without feeling green.