I don't know if there isn't already a thread about this, but seriously, WHY can't we fight reconquest wars for our vassals/junior PU? Back in Crusader Kings 2 things seemed to work much better. If I'm King of England and Scotland I can always demand the de jure borders of both my Kingdoms. Cores are similar, but I find it odd that we can't use whichever CBs our vassals have/would have. I know I can DOW for whatever reason and then demand "Return Cores", but I still think that after Dipplo-vassalazing Norway I should have a reconquest CB against Sweden. A PU between England and France after a victorious HYW campaign should allow the King of England to demand all French cores from Burgundy/Provence/Whoever else stole them.