Stupid question... What would be the best direction of IR ?

This affects the PCB design.

• A = USB connector direction (i think it is this)
• B = Where the camera points
• C = Left
• D = Right

The transceiver can be mounted in top view or side view, so the option B will be possible with any other option.

Option B only will make smallest PCB area.
With option A, have to go around the camera...