I'll continue reading that thread and post here if anything new comes up.
edit: read to the end of that thread and it didn't really come up with an alternative solution to the above. So, it seems the best solution is to go online and race with real people, or just let the AI pit at the same time and accept that they're not quite perfected yet !
We've raced some AI's a couple of nights, and the only solution we could think of, is this. Giving the AI a stop and go "/p_sg ainame" before the last split and then when it has reached the point of no return, you clear it "/p_clear ainame". They will stop for 10 seconds anyway, but it still counts as a pit and they will take on the fuel needed. Of course it will have to be done before the others pit, but at least it takes a load of off the pits.
I know LFS isn't supposed to support this kind of thing, but we've had some fun with it, thus it would be nice