Could you consider adding a mouse centric way to simply transition from an ortho view to the free rotation of Perspective view. Having to explicitly click a perspective mode button seems unnecessary. For example, I frequently go into bottom or side view to place supports. To check I want to freely rotate the view but to do that I have to reach navigate away from the graphical view, click a button for perspective, and then navigate back again. Hunt and peck like a chicken. It seems ortho views don’t have view rotations about their normal (?) so a simple middle mouse click could instantly flip to perspective view and enable free rotation right then and there when and where I want it.
By way of example, Zbrush has a different mechanism, but the manipulation is smooth. Hold shift while rotating and the nearest ortho view is toggled and snaps into place. When done just rotate again as normal.
Similarly CAD like Inventor or Fusion 360 offer view cubes to select an ortho view. Formware has it’s icons so no problem there. However once engaged the user is not locked out of free rotation like the present situation in Formware. Just rotate as usual and the ortho view is gone.
Regards