Open 0xr.space on the Quest and open a model. Pinch it with both hands, or hold both triggers if you use controllers. Pull your hands apart to make it bigger, bring them together to make it smaller, and turn them round each other to rotate it. A model standing on the floor grows from the middle of its base and only turns about the vertical, so it does not sink or tip over.
Two hands scale a whole model between 10 cm and 10 m on its longest side, and stop there. Let go with one hand and the other keeps carrying the model, without a jump. This needs a headset: on an Android phone in AR, two fingers on the screen scale the model instead, and on a computer the mouse wheel does.
Press More on the dock, then Gesture Help. The Scale & rotate row shows it. After you have carried a model with one hand a couple of times, a short animation also shows it, until you have used it once.
Yes. Press Scale on the dock, then Real-World Size. Fit to View brings it back to a size that fits in front of you.
Two hands stop at 10 m on the longest side, and at 10 cm the other way.
Yes. Hold both triggers and move the controllers the way you would move your hands.