What’s your philosophy on dragging the toe on the back foot?
I never thought it was much of a philosophy and more a by product of mechanics.
I’d be interested in hearing people’s philosophy’s as well
It’s not really a problem unless it’s limiting or slowing down rear hip rotation. If the pitcher has good tempo while dragging the toe, I’ll leave it alone.
Isn’t that how you throw change-ups? 
But seriously, failure to drag the back toe might be an indicator of some other issues (e.g. posture issues).