Other thing to note is the wear on the rear spline is much more advanced than the front one as the rear is made of aluminum and the front, steel. The drive belt is catching all the flying debris and gradually wearing down the teeth. Enough to see and detect a difference. Front appears to have minimal wear.
Do you think it would be prudent to swap for one made of steel?
Have no idea if any are made of steel. Aluminum makes too much sense on the rear wheel in order to reduce weight. Everyone is doing everything possible to reduce weight for emissions and handling.
What's your mileage? Who cares. Is it practical? See #1. What happens when it rains? You get wet.
