This is a little theory of mine, though I'm not much of a scripter, so I don't know if it would be possible. Basically, in Oblivion and Skyrim, doors use an animation to open and close, but in Morrowind, the engine just rotates them on their axis. Therefore, to make double doors that open properly, you have to resort to weird trickery and you can't get the double doors to open and close together. You also can't make doors that open in cool ways like roll open or open like an iris for example.

Now one way to solve this problem is to use activators instead of doors, the activator would play an open or close animation when activated, therefore, problem solved, right? Well, no, there's another problem associated with that, NPC's won't be able to open your door.

However, if one would be able to place an invisible door over the place of the activator door, that would activate the activator door's "open" script, NPC's would be able to open the door, and you'd have a functioning door that used a custom open animation.

So, is this possible? As I said, I'm not much of a scripter, otherwise I'd have gone and tried to figure it out myself. However, I'd like to include some doors with custom open animations in my mod and would like to avoid any issues with NPC's not being able to open them, so this loophole would be a nice alternative. I'm sure others would appreciate such a workaround if we could figure it out as well.