As I understand the sketch surface, the red and blue axis define the normal plane (the “ground”) on which your model is anchored, and the green axis represents the vertical direction. Using the orbit tool, it’s easy to rotate a model around blue and red axes, but if you want to rotate it around the green axis, you need to use Cntrl/Orbit. But when you release “Control,” the model reverts to the last orientation it had with respect to Blue/Red.
I must be weird, but when I construct a model, once I have the plan form laid down and the vertical (walls, e.g.) pulled up, my preferred way to navigate around the thing to add features is to rotate it around the green axis. But one cannot “maintain” that orientation. Very frustrating.
Am I not understanding the logic, or missing some feature?