Working on adding a start date in the 1400s, as well as (later on) one in 1453. Trying to set up the Kalmar Union right now - I've created the title itself, but in-game, it creates problems with respect to how the subordinate kingdoms (Sweden, Denmark, Norway) are inherited, with them all going to different people rather than maintaining the personal union.

Is there a flag which can be placed on the titles which will prevent them from being created by subordinate lords who are part of the KU (thus permitting me to remove those kingdoms from the start date altogether)? Would appreciate thoughts (or if anyone else has any other ideas for workarounds in mind).