O, this would be an awesome expansion for when your heir turns of age! Like this event fires off to acknowledge how well or how terrible your heir is and then it gives the option to possible have the realm swear fealty in the form of a "grand wedding."
I know this isn't very historical, and comes more from the House of the Dragon, but it would add more depth to raising a child. To balance it, much like others have said, it can come with tyranny points, the risk of new factions forming, hooks on the liege, strong relationships, weakened relationships, etc. Also, maybe this option can only fire for someone with high prestige and specific traits (diplomacy/martial education, ambitious, authoritative, diligent, arrogant, paranoid, family first, etc.)
Okay sorry for the long post! Thank you so much for the mod c:

@ NewOppPack

No worries, I enjoyed reading it! Unfortunately, I have been otherwise occupied with other duties and I haven't been able to get as much work done as I would have liked on the upcoming mod, so I couldn't really give a final structure and capabilities, but I do plan on trying to make the interactions more varied with outcomes sort of similar as to when you send a letter and get rejected on this mod -- but to a greater extent, not a one-click outcome. I appreciate you writing the comment and I am very glad you enjoyed it!