We can't add any before the bleeding years not because we don't want to but because the ck2 engine doesn't support having multiple maps.
That would basically require us to rewrite the entire mod to fit that time by adding in hundreds of thousands of new characters into the mod. So imagine the time it took for the mod to get to this state and we would have to do that again, would be a pain especially for the history guys.I'm don't know really anything about map modding but is it possible to have like the main game has the current map and if you wanted to play a before the Bleeding Years scenario you could check a mod in the launcher screen that will start the game with a map where Old Valryia is still around but you can't play any scenarios after the doom?
This also gets suggested every few weeks and here briefly is why we are unlikely to ever do it:I often don't use the bookmarks. One of my favourite houses to play is the Webber's of Coldmoat, I often play ast their first count who starts somewhere around the middle of the time line IIRC. One new start date I would like is A game of thrones. So you can start exactly where the story begins. Have a little event chain for Ned Stark revolving around the Jon Arryn murder mystery. I think that would be cool.