Keep your AB drive tensioners parallel and belts running true / centered on the idlers.
The rev 1 style AB drive tensioners have the tension screw offset from the idlers which can lead to the idlers not running true with the belt path. The belts will drift to the edge of the idlers and end up with wear along the belt edges.
Scale Z on this part to match your printer's spacing/gap in the AB drive tensioners. They should friction fit.
The author marked this model as their own original creation.