Background: I'm tediously playing a 29ktile donut map and terraforming the rather large poles with nearly 1000 engineers. I have a patch that does connect-with-transform, but even that seems inadequate: mainly because I forget which engineers are terraforming along which path, so two paths end up intersecting and I get tiles terraformed more than I want, or at least sooner than I want them in the desired state.

It would be nice if the client could display the state of the world as it will be N turns ahead - at least to present an approximation. Of course it isn't possible to predict barbarian or other enemy interference, but it would be good enough to approximate the future.

A time machine could also be useful in planning decisive battles, but doing that properly would need a lot more UI in order to explore the ensemble of possible outcomes by considering various enemy actions.