Mounting Encoder to WCP DS Gearbox

I’m new to mentoring electrical, and I was wondering if any team has any suggestions on which encoder they like to mount to a West Coast Drive Dual-Speed gearbox, or if that’s even a worthwhile pursuit. If you are mounting it to the gearbox, how are you doing so?

We have access to a 3D printer and can make our own mount if necessary, but would prefer to go with a tried-and-true approach instead.

Thank you!