Since some of the scenarios involve a lot of waiting, I often find myself a bit bored while waiting for research or for enough profit to rack up for me to win even on fast speed. If you added another game speed that was twice as fast as the fast speed, that would be nice for those times when you need to settle in for a long wait.
Alongside that suggestion, it would be nice if the game automatically kicked back into 1x speed or even paused when you got a notification that research, analysis, or exploration is complete. When in fast game speed (especially if a faster speed is added) it would be nice if I was able to react faster to events like that. Maybe make it an option that can be set but is off by default?