On my 2020 FX the front sprocket "shattered" according to the dealership, which caused damage to the splines on the motor output shaft, and necessitated a motor replacement. Fortunately it was covered under warranty, but makes me wonder if this could happen again once the warranty has expired. I don't see any markings on the front sprocket, but there are no holes drilled like in your JT diagram. Has anyone else had their sprocket fail on a new Zero FX? It broke when I drove over a small pothole. I upgraded to the chain kit after the belt broke when I fell in some sand. I thought the chain would hold up to dirt riding, but mine didn't last more than a month. The new sprocket has a couple months of riding on it, so maybe it is better, but maybe I should put an aftermarket sprocket on that has a good reputation.