I haven't dug into an A1 with the circuit board. Do you have TB1 under the circuit board?
I wired cameras to the turn signals and the reverse light but it was on an A0. I tapped the left signal at TB1-48, the right on TB1-44 and reverse from the 490 wire coming off connector P51 (in the dash).
Not sure what camera system you're using, I just used a screen with 3 video inputs; no birds eye view fanciness. I had to use off-delay relays for the turn signals or my screen would flash on/off with the turn signal.
Hopefully that's useful but if not, it was free.