Hi, initially there is not any option to clip a segment, because this operation is not efficient for the instancing engine (each board should be generated as a different geometry).
Instead, it's possible to resize it using a Transform operator, enabling "Fixed Size" and exporting the X or Y size parameter. To avoid that the scale operation deforms the UV mapping, use Segment->Deform->Mapping, which generates a continuous mapping along the RC object, regardless of the scale changes.