Zipline usage amongst the player base.

Last night I built a zipline connecting the mountain ridge just west of South Knot City to the Timefall Farm. I’ve always 5 starred those locations but I figure other porters can have a neat short cut instead of having to trek the rough terrain and river, or having to go all the way around towards the Weather Station.

I never see other players zip lines though. Can they see mine? Is that much later in the game or is it something you don’t see so as to not break the game?