This is my design for a stable, secure mount for the X-axis opto on an Orca 0.3 with the standard opto-sensor.

This is much more secure than the official cable tie approach, the M4 bolt keeps the part secure to the M8 rod and stops it moving left or right.

Print one of the part.

The part fits over the M8 threaded rod, and is secured with an M4x30 bolt and nylock. The opto-sensor is secured using the 3mm holes on the opto, with M3x25 bolts and nuts/nylocks.

The opto-flag will need to be straightened again if you have already angled it for the cable tie method.