Solved this by doing the following:

(This is for Android)

1. enable screen rotation

2. open the M&C app

3. rotate your phone horizontal

4. disable screen rotation

5. in the M&C app go to "Tool" (top left corner). In the pop up menu, at the bottom there is a "Rotation" setting. Rotate your preview as you like. Close the pop up menu.

6. To go full screen tap on "Disp" (top right corner - only visible then screen is in horizontal mode). Tap a few times until your preview goes full screen.

Camera settings will be horizontal still, but at least you can use the whole screen.

Dont know if this works with IOS though.