Interacting with dungeon entrances/exits should be the same as activating a node on a maproom. There should be a delay where you are vulnerable to attack instead of being instantly teleported to the safety of a loading screen, which ruins pvp engagements when someone can just repeatedly enter and exit a dungeon to avoid damage.
Like teleporting to an obelisk, players are already invulnerable to damage while they finish loading in and for a few seconds after. This is more than enough time to enter/exit the dungeon again and repeat the cycle. This is not an issue with Obelisks because, 1: You need to travel from an obelisk to a maproom in order to teleport again and 2: teleporting using a maproom isn’t instant.