How long does it take for a shared vision ai script to take effect for viewing cloaked units? I know it can vary, but does anyone know the longest time amount?

I think nobody KNOWS it but from my experience never more than 5 game seconds.

I know you lose vision every 4 seconds. It could be that way for shared vis too.

Hypers and Game Speed would change the speed of vision right?

Not hypers, but game speed certainly would. Hypers would only affect how fast the trigger actually runs.

Hmm. I've had vision update just by creating and removing a unit in a spot, inside the same trigger, so often times it is instant.

Creating and removing a unit makes the shared vision thing happen faster?

I don't think so, but perhaps. In my map I constantly give a unit to the player, then immediately give it back, in the same trigger, and they receive constant vision to the spot.

If it isn't compiled every update, a new vision map would be compiled on a regular basis, irrespective of events on the map. Testing could probably reveal the number of updates between compiles, and then it just depends on when your vision action executes as to how long you have to wait.