As requested by a user ( Fantastic Fwoosh), this version allows player-run CNs to merge with other CNs who share an overlord. The overlord must accept the request (only matters if MP, AI will always accept).

https://www.dropbox.com/s/yrgvgyuigqqsxu5/CNMergeExperimental.zip?dl=0
Extract it to *Documents\Paradox Interactive\Europa Universalis IV\mod*
## If you use this version, unsubscribe from the main mod! ##

How to use:
-Mark another CN as your merge-interest. It is a diplomatic action, influence tab.
-Ask for permission to merge with your overlord. Same deal, influence tab.
-Done.
-You can cancel the process anytime via diplo action, too.

Extra care should be taken if in MP, as well as player cooperation and responsibility. Always wait for players to complete their merge processes before starting your own, and there should be no problems.