First time using TPE. Overhangs are pretty rough on a MK3. The rubberiness of TPE is more like a vulcanized natural rubber used on surfaces like conveyor belts. It is similar to bike hoods. That first textured print is still too rough and rigid for a thing like bar tape.
In terms of the part itself, it is a termination point for the handlebar tape so that the shifter body is not integrated into the bar tape and can be removed if needed. I am testing a printed index mechanism, so maybe I am the only real use case.