Does Cadrage use all cameras of my iPhone?

Yes, Cadrage uses all available cameras of your iPhone.

The ultra-wide camera will always be used automatically when necessary to simulate wider focal lengths. Because the regular camera has better low-light performance and close-focus capabilities than the tele camera, you can manually switch between the two by using the 1x and 2x button (some models have a 2.5x or 3x button instead). This button will display only if applicable.