I feel like we could do with some choice that might seem not seem initially helpful, for example to fix the case of enemies taking cover on your Bulwark Sparks I think you should be able to turn the cover on and off (like you could with all for one in EW), and this would be a free action that you could toggle infinitely (like closing or opening a door.), this would even synergize with overdrive since you could toggle even after using all three actions.
Also it'd be nice if you could willingly give up liberated regions (return them to unliberated state) without failing an invasion and losing all your rebels. In this way you could funnel power from one region to another, instead of having advent strength too concentrated because there aren't enough regions they can occupy.
I feel like toggling liberated states wouldn't be too difficult, but toggling bulwark might, if it even matters.