a. Increasing the amount of time that messages appear on screen (the yellow kind).

b. Increasing the amount of time that floating info (damage, in particular) appears OR making a yellow message pop up when your guys take damage.

c. Slowing to normal time for enemy shots (or perhaps for visible/audible enemy actions in general).

a. Adding items (and possibly skill checks) to monitor enemy radio chatter, allowing you to be notified when an enemy has called for reinforcements and possibly giving you additional information (NSEW direction, force size). Chance to intercept and the amount of information could be tied to WIS/LVL, character status (suppression, energy) and possibly electronics proficiency. Could also be a sneaky way of influencing merc morale (hearing that fifty enemies are on their way ought to have some effect, right?).

b. Less complicated might be allowing the already (too) useful Scout trait to give a character an indication that enemies are on their way (rough group size, direction) within, say, a turn or two. Alternately, just some indication at the beginning of battles to Scout characters/mercs with binoculars/good scopes what directions enemies are likely to reinforce from and in what numbers. Again, this is something that could be tied to skill checks and condition.

c. Radio interference equipment, to prevent enemies from calling reinforcements but also denying the ability to command militia out of sight and automatically killing the you-see-what-the-militia-sees setting. Could also increase heftily the penalty to hit out of sight enemies (assuming that usually that's possible because a spotter is giving the shooter directions via radio). Could be made combat pack sized to balance a bit (for whatever reason, I kind of like the dedicated radio guy role).

d. Allowing enemies to call reinforcements upon 'seeing' your mercs advance and letting your mercs know the amount that they've beefed up (under conditions where your mercs would know the enemy force size to begin with). Could be prevented using a Hunter/Ranger character. If the enemies call reinforcements this way, they shouldn't be allowed to call any more during battle.

-Barracks: Either in place in appropriate sectors or makeshift, used to influence perhaps maximum militia size. You could make upgrades the prerequisite for training normal/veteran/mobile militia. This would strike a balance in my mind between the abysmal uselessness of militia at higher difficulty levels when you have 20/no veteran and the wild game breakingness of 20+/trainable veterans. In important sectors, you can pay a lot to achieve that unassailable 30 veterans, but it's hypothetically too much of a pain/too expensive to just flood towns. Scaling leadership checks to create different improvements, no manning required.

-Watch-towers: Take away magic militia spotting and make this necessary to see enemy numbers in adjacent sectors. Maybe use it to increase auto-resolve strength a bit. Basic mechanical (?) check to create.

-Manned workshop: Upkeep cost, but automatically repairs items in the sector inventory. (Could do similar for field hospitals, garages, or even training ground to automatically top up lost militia with greenies.) Basic mech. and leadership (or medical and leadership) check to create.

-Radio station: And broadcast jingoistic programming to increase loyalty by a smidgeon at the cost of an increased pool for the queen/more aggressive AI or make it pacifistic to reduce loyalty while decreasing the queen's pool. Also makes this sector a higher value target. Mech. check to create, needs to be manned by merc with leadership (boost to in country RPCs? Miguel should get a fantastic bonus to jingoism, Ira to pacifism).

-Munitions factories: Use the ones in place to generate low quality equipment (or even make control and operation a prerequisite for training veteran militia in a sector) like common ammo and explosive types. Make creating cottage industry factories possible for the most basic ammo, with a risk of an accident that would drop loyalty. Basic leadership check and no manning to get basic operations, but perhaps make more complicated things contingent on merc manning (e.g. explosives merc determines the quality and quantity of grenades produced (I'm thinking something like 100 EXP merc could do mortar shells with an extremely low chance of accidents, 70 EXP merc could produce frag grenades with a moderate chance of accident), mechanical merc for ammo).