Screen Rotation Orientation Options

Based on my use, the screen rotation movement achieved by moving my finger up and down is based around the X-axis, and rotation left and right is based on the Y-axis.

This means that if I set my camera using the top right orientation cube to look at the front of my model:
-I can move my finger up and down to look at the top and bottom of my model.
-I can move left and right to tilt my view model clockwise and counter-clockwise.
-I can try to rotate around the Z-axis to get a look at my model from the left and right, which results in a simulation of my model tumbling down a flight of stairs.

In future versions, please include a way to rotate laterally around models using the Z-axis as the basis of rotation. It would really help when trying to, oh I don’t know, show a client an architectural sketch of a rear deck without having to use the drunken trackball technique to show them the whole thing from various left/right side angles.

…I have discovered that by double-tapping the orientation cube, lateral Z-axis based rotation begins. And when navigation gets weird again, double-tap-cube. Returns things. Is thus documented anywhere, or am I just lucky?