

Legacy of the Dragonborn *can* be added mid-game, however there are three special items added to the game world which won't be available if you already played through the quests relevant to them during The Man Who Cried Wolf, one of the people trying to raise Potema wears a slightly bonkers enchanted helm, during one of the later Dark Brotherhood quests - possibly the Grand Finale type one, I can't remember, anyway - you will be able to find the legendary sword Goldbrand, and, er, I can't remember the other one.

Also, make sure you only give them commands (wait, dismiss etc) through EFF. EFF can usually be installed mid-game, however you must make sure you dismiss any current followers and save the game like that before you activate the mod, or EFF may not recognise them properly.
