I used and tested a lot !!AI receiver. So far AI will do a good job if the target is at no more than 2-3 days, and possibly in rather straight line. If you set at higher distance, there are big chances the game crashes. When AI can't find a travel algorithm this will trigger unpleasant results.
For example in tew4 labyrinth I asked AI to go to destination. There were no blocks, no objects in the path, but a labyrinth design, with a lot of corners and dead ends. Game always crashed as soon as AI got the code. In 300 spartans, same code said to 60 AI heroes to do same ~straight line then attack, after a 2 days travel. That one worked perfectly.
So, imo, if you need a timer, it means the distance is big, and so will be the risk.
(This post was last modified: 03.09.2015 19:55 by Valery.)