In 2013 some teams (see 254) used antennae like components that stuck above the machine and bent back when positioned below a rung of the climbing structure. This provided vidual aid in knowing position for shooting, but I reckon it could assist in accurately positioning at the edge of the colour wheel.
What material was used for the antennae way back then? Is there a better material available nowadays or a better passive mechanical solution for lining up?
Needs to have a high elastic point, so rubber was my first thought.