You might remember
Grymforge Travel CheeseThere was also
Fast Travel Limitation Poll and others I'm sure.
I'm not against the portals, fast travel in service of player convenience is something I'll overlook to a point, but when you start being able to cheese exploration, and dungeon crawling, it becomes an impediment.
I saw someone ask how to reach the Temple of Shar recently, and all I could think about was what might happen in the final version of the game, where someone featherfalls down, finds a portal, and bob's your uncle. There's already a place in Grymforge where you can bypass a party splitting exploration challenge by just cheesing everyone over with the portal.