Gateway Seeds - An End-game Way to Travel Fast

This idea has been floating around in my head for a while now: what if there was a feature that allowed you to generate a pair of End gateways--like the ones scattered in the outer End islands--wherever you wanted, to link up bases and travel extremely long distances in no time at all?

Now of course, it can sound super overpowered, and you may also be thinking, 'This is what Nether portals are for'. But that's where specifics come in.

I imagine this item, this 'Gateway Seed', as something you'd find very rarely in End Cities, or maybe even End Ships in place of Elytra; not craftable at all. It'd generate a single End gateway about 6 blocks above wherever you use the Seed, which wouldn't go anywhere until you spawn the second one, using the Seed again, in a different location. You'd have to travel to whatever location you want to link the gateways up in, but as soon as you do, you can use it. You'll end up on either side, either way, immediately. 

This tool would be useful for multiple reasons. It would allow players to go between important places that are far away without much hassle, specifically, but it could also be used in multiplayer games as a way to connect locations, or even as a device to raid bases in PvP games with.

Whether or not it could go between dimensions is up to debate, and there would also need to be some way to remove the gateways if players want to get rid of them. Suggestions for these ideas in the comments are greatly appreciated!