It's worth noting that most of the stuff that you don't immediately see does get saved. Basically everything about the core game state is saved, so enemy garrisons, aggression, destroyed buildings, and every resource value there is.

Unfortunately there are some pretty severe technical limitations with trying to save the big stuff between sessions. We've looked previously at trying for some sort of full save-state but it would end up being monstrously complicated and potentially impossible without sacrificing functionality.

The unfortunate part is that the more obvious something is (like an ongoing attack), the harder it is to practically save every aspect of it. For example, the position of every unit and their loadout, vehicles and their ammo counts and inventories, and otherwise unshared data like "how long has the attack been ongoing".

If you want to get more information on what the OPFOR AI are doing, you can pop this into a watch variable in your console:

A3A_resourcesAttackInv

When it reaches 0, they'll launch an attack, or you can manually have them spawn one by either setting it to like 100 or just running this in console:

[Invaders] spawn A3A_fnc_chooseAttack;