Is there a way to constraint the knife tool to a global axis when I am in a random angle of view in the viewport:(?
Hi there! Maybe it’s too late but I have an answer.
There is no way to do exactly that, but you can:
Change the view to side/front/top view either perspective or orthographic and then press C to activate Angle Constraint. Now your cuts are constrained to 45 degrees angles, so the perpendicular ones are in fact aligned with the Global Axis.
Hope this may help you and someone else!