How common and fast is aetheryte teleporting?

[Jandor]

There was a comment when you met up with the Doman Resistance that they smashed the aetheryte at their base I can't remember the name of that, when the Garleans were trying to stamp out the last traces of the rebellion, they were trying to force unattuned conscripts through. I forget if it was mentioned what happened to them.

A lot of them died I guess.

It's possible to teleport to an unattuned aetheryte, same as it's possible to drive down a busy road with your eyes shut and the music turned up.
Got a vague idea of where you're going, there's a chance you'll make it to the end intact, 100% not recommended but you might give it a go if someone held a gun to your head.