[Sugestion] Coupler Block with 4.5 mm steel ball

[klone52]

There are cheaper and easier to find 4.5 mm steel balls in airsoft ammunition, with great diameter consistency. For this you would have to move the pre-gate switch closer and decrease the diameter of the hole by 1 mm.

To make it backward compatible with the kit's PCB you would have to bring the switch closer and make space in this way: