Is it possible to mod the Territorial Expansion penalty? To make it more severe?

Lately I've been thinking that the "territorial expansion" penalty for diploamcy might be too low. In my current Takeda campaign, I've taken several provinces in the last few turns and my territorial expansion penalty is only -19. Compared to other penalties, this isn't very much. In many respects, taking provinces is the most threatening thing you can do to the other clans (besides specifically attacking them). As the player, I know I worry much more about the AI clans that are getting really large than the ones who aren't expanding much.

Also: higher territorial expansion penalties would smooth the transition from being aggressive prior to realm divide to actually hitting the number of territories that triggers realm divide. If owning 18 provinces triggers realm divide, you still should have a high territorial expansion penalty at 15 provinces. After all, realm divide is just the ultimate territorial expansion penalty.

Do you think that the territorial expansion penalty is too light? Do you know if this can be modded to be more severe? Maybe your territorial expansion penalty should be more for each province as you get bigger (and therefor more threatening). Thanks in advance.