Permanent Cores
This mod changes how expiration of cores works.
As you know, normally, most cores expire when the country losses control of the province for certain number of years. The only exceptions are primary tag of the culture of the province.
This mod changes the default time of core expiration from 50 years to 1000 years.
It also makes it so that cores of the same culture group do not expire.
Note: Cores can still be revoked via peace deals and destroyed via events.