I use the Quest for standing/untethered movement, so I always default to standing. This meant my head was clipping into the 'thrusters'/exhausts of the hot-air balloon throughout the flight. Once it started to turn while ascending, there didn't seem to be a way to stop it, which meant it rapidly became a test of VR vertigo. I've got good VR legs, but that wasn't very pleasant. A hot air balloon should be as pretty an experience as possible, considering how limited your interactions can be. Some clouds (which can help define altitude gains), some water/hills/mountains to vary the terrain below, maybe a simple procedural sun?