When an expansion has been announced, it's probably to late to wish for things to be included, but I will throw my hat in the ring anyway.
What I have missed in all of the HoI-games, is a percentage-slider allowing the player to control how much of your basic IC that are running (or rather at what level the industry is working). As it is now, once the ICs are in place, they run full tilt until they get a raw-material shortage, and then a whole bunch of industries abruptly shuts down. An influence over this could make for better planning. In dictatorships this would be easily achievable, and in democracies we could chalk it down to the market forces at work.
The slider might even go up to 110% for those special national grand efforts, but with the side-effect that after a while random industry points would suffer breakdowns similar to being strat-bombed. They would have to be repaired back up again in the same manner as after a bombing. The degrading effect could be affected by how high the slider is set above 100%, and the time it has been there. Perhaps also modified by national unity, on the basis that the more you are behind the regime, the harder you work to keeps things running.