If you have access to CNC machines (through your shop or via sponsors), you can machine your own sprockets. The Denso motors also do not like cantilevered loads, so you should always support the shaft with another bearing/bushing. Here's some 7075 aluminum sprockets with a Denso hub pattern that I machined last year for 228.
The Denso motor, sprocket, and shaft support (with Delrin bushing).