Missing FLOW parameters?

I am attempting to get a Micoair MTF-01 optical flow sensor working on a Matek-F765-Wing running ArduCopter V4.5.3. I believe this FC should meet the requirements and have reviewed the features.txt file to confirm optical flow was enabled in the build.

I am able to view the rangefinder and optical flow Mavlink messages in the Mavlink Inspector and correctly see the rangefinder data in the Status window. No data however shows up on the opt_x or opt_y despite these values changing in the mavlink messages.

Hoping someone may be able to offer some insight into why I might not be seeing these FLOW parameters and/or if setting FLOW_TYPE is required to function?