Aetherytes, Garleans, and You!

[Yuriane]

Based on how there's a cable linking the transporter gate to the destination, we can probably guess at how they work. Garleans can't manipulate aether but they are still comprised of aether like everyone else. If a Pure-Blooded Garlean were to try to use an aetheryte, best case scenario is nothing would happen, worst case is their aether would dissipate and they'd die. I posit that the transporter gates work by breaking you down into aether and then transferring you safely through the cable, then reconstructing you on the other side.

Regula's teleportation was likely a wireless version, connected via a pair of beacons within his armor and the Gration.

[YianKutku]

Also there are Magitek Transporters in Dzemael Darkhold, along with various "stand in this to activate" magitek devices, for some reason. (Seriously, why the heck would anyone build a device that only activates when someone stands in it and twiddles their thumbs for a minute?)

I don't recall if the transporters have wires leading out of them.

[Mysterysword]

Seriously, why the heck would anyone build a device that only activates when someone stands in it and twiddles their thumbs for a minute?

Note that most of those devices happen to be in rather hazardous areas. Off the top of my head, only the first and last sections of the dungeon have them. In the first section, we see those devices everywhere, apparently being used to trap the ahriman flying around in those tunnels, and none of them were inside the purple protection crystals. In the third section, we have two blue circles at once, both smack dab in the range of giant exploding crystals.

So maybe those devices weren't actually the main way to open the gates, just really stupid traps that somehow allow intruders to unlock the gates if they survive long enough.