I think if you copy the pre-existing mod, and then alter that copy (rename it, then add whatever events you're trying to add) it should work just as well as altering the mod, and you would be able to choose which one to do. Just be sure to not have them both active at once.Alright I've managed to make some improvement. I decided to switch back to altering the pre-existing mod to see if it'd work and it does. In fact, it works so well that the game can actually read one of the events I wrote. It's just showing up as a blank event, but that's an improvement right?
Having a blank event could either be a problem with the event or a problem with localization. How familiar are you with event modding and localisation? If you're not particularly familiar, check out the wiki pages I just linked and see if they help.