The first time I ever heard the term "pinning" was in a blog by Kaeko in regards to how he was able to hold Jailer of Temperance by positioning himself across the room and moving slightly left and right to confuse the NM's pathing. Even though the NM moves substantially faster than the player, it can be held in that manner for an extended period of time, with some skill.
https://kanican.livejournal.com/10864.htmlPinning on Nasomi has come to mean something different than in retail because the draw-in, teleporter deaggro, and general path-finding all do not work as well as retail. The line between abusing a teleporter and just using the tactics available at your disposal is a grey area. For me personally, I would argue that anything the draw-in and teleporter mechanics let me get away with, is fair game. Basically I would say it doesn't become "pinning" until you don't have to do anything, and the monster still can't get to you. If you're having to do something, be it taking teleporters, or just moving slightly left and right to glitch the pathing, now there is retail precedent for your tactics. That's just my opinion though, and if you do it you're gambling Nas sees things the same way.
I don't know that the comparison to an HNM really holds up, as the HNM all have countermeasures in place to handle this contingency, even in places retail initially didn't. If sea ever gets a navmesh and you're wondering if you can pin AV, my advice is: don't try it.
Seems to me like the ball is in nas's court to add some deaggro on teleporter use in riverne site.