Going back to the mid drive and torque part of the discussion, for serious off road use you would not use a 28T lowest gear. Typical mtb cassettes these days are 50T or a few more, which multiplies your 28T torque figure by 1.8.
Keep that in mind if your hub mods don't get you what you want.
Keep that in mind if your hub mods don't get you what you want.