An apparatus for labeling support structures includes: a chassis having a locomotive assembly, and supporting an effector assembly with an end movable relative to the chassis and carrying a label modification unit with an image sensor; a controller coupled to the locomotive assembly, effector assembly and label modification unit, and configured to: obtain label modification data defining a location relative to a support structure reference feature for a label modification operation; control the locomotive assembly to travel to the support structure; detect the reference feature via image data captured at the image sensor; control the effector assembly to place the label modification unit at the location relative to the reference feature; control the effector assembly and the label modification unit perform the label modification operation.