I got the Maestro working with HRN-HRR-T01 on a 2005 4runner limited with a Pioneer DMH-W4660NEX , with the exception of the backup camera, and the following connections: illumination, parking brake. The problem is that the harness HRN-HRR-T01 doesn't have plugs for the backup camera (4pin, arrange in a 2x2 plug) . And since there's no illumination, I get no dimming of the head unit when I have the lights on (leading to a glaring display at night) and as there's no parking brake I imagine I wouldn't have any HDMI video.
Fortunately I have the pinouts for the connectors on the car side, and will have to make my own harness but this is not an out of the box solution.