• Development time first: one custom 0.5 mm FPC, compact, easy to route.
• One pinout for every camera, 4-lane or 2-lane; a 2-lane camera leaves the last two pairs empty, so cameras can swap later.
• One connector on all nine ports: XF2M-2015-1A. No regulator on any camera module: the carrier supplies 1.8 V, 2.8 V and the core rail.

The nine camera ports

The one camera tail

• Carrier side: the host switches the three rails on; I²C pull-ups are on the carrier or SOM, none on the flex; 100 kΩ pull-downs on reset and FSIN.

Sources: the two flex specs in the headset repo (boards/camera-module/docs); both move to this tail.