It might be in this thread somewhere.
The 2 wires in that connector that contain the camera feed are white/green and brown/purple, you can tap them and connect an RCA plug.
After a week of reading a couple of pages of that thread each day, I think I may have found the answer but I still need to confirm by checking with a multimeter.
of that thread you shared claims there are five green/brown wires
but also provides a link which brings us to post #46
of another thread, which claims the reverse light wire is "green/brown" or "green with a brown stripe" located at pin 44 of a brown 46-pin harness connector. I really hope by "reverse light wire", they mean "reverse signal".
Now, that post is for a green/brown wire of a brown 46-pin connector that's located underneath the dashboard. If I'm not colorblind, I've identified a wire with that exact same color combination in the harness where the tow module is supposed to be as shown in the pictures I've shared above. I'll check with a multimeter to confirm and report back when I have time, which will probably be this coming weekend. Thanks for all your help so far! I hope to come back with good news.
Between now and when I have time to check that wire, perhaps someone who has checked that harness leading to the tow module can confirm? Thank you!