There has been mass-null tech for decades now. The only reason G forces affect you is due to inertial mass; you tend to want to stay in motion. But antigravity (or should I say more accurately “null gravity” because it’s simply being blocked) isn’t just for up and down motion. It becomes superluminal and the craft can go side to side, front to back, rotate, pitch/yaw all with the participants feeling like we do on this planet spinning thousands of miles an hour and orbiting tens of miles and hour, and hurtling hundreds of thousands of miles an hour—all while sitting perfectly still in a chair think were not moving.