Factory/Resource Upgrading: Completely new feature allowing upgrading of rebel-held factories and resources using a new button "Upgrade Assets" in Battle Menu (Y key by default) > Commander > Commander Menu > HQ Tab > Upgrade Assets.

This feature allows spending increasing amounts of money to upgrade rebel factories and resources to increase their yields, making tall gameplay (holding a few quality locations only) instead of wide gameplay (conquering more and more locations) more viable for stable economic gains.

In summary, any rebel factory or resource marker can be upgraded for increasing cost steps set by a the related parameter to yield up to 400% gains of an unupgraded marker.

In details:
All factories and resources start at level 0 and rebels can upgrade theirs up to level 3, getting the base yield + 100% more yield with each upgrade, up to 3 upgrades for any marker.

Each upgrde increases the cost of the next upgrade by the increment amount set by the parameter and this applies globally for all rebel markers, not just separately for any factory or resource marker. For example, if your first upgrade is on a L0 resource to L1 for 10.000 money units (increment step being 10.000), your next one will cost 20.000 whether it is the L1 to L2 upgrade on the same resource marker or any other marker, even if that marker gets from L0 to L1, or L2 to L3. This is implemented to lower the reward/cost ratio in the late game when you can have a lot of factories and resources, so you shouldn't profit exponentially.

Upgrade costs being the total upgrade count + the next increment amount, a lost factory or resource marker with upgrade levels in it will lower your current total upgrade count, thus the upgrade price for the next one.

Losing a factory or resource marker does not reset their upgrade level so as not to throw away all those mid game upgrade expenses, but still lower the upgrade level by one, so that holding on to an upgraded marker is encouraged. This level decrease happens only when the marker changes sides from the rebels to occupants or invaders. It does not happen when rebels take a leveled marker back, or occupants/invaders take a leveled marker from each other.