...due to choice overflow that doesn't fit the event window frame. This means that you get the choices still listed though, but you cannot click on any choice beyond the end of the event window.

So you open up the Character Editor Event through this mod and then click into "spawn children" or "Add Modifier". The list from options you can choose from is so long that it exceeds the event window's borders and as such is no longer clickable by the player... This kinda is a one-way trip, as you cannot continue the game with this event freezing the time.

I'm a bit buffled that noone ever brought this up, didn't this ever happen to anyone before?

Because it makes you get stuck in "add children's" selections or "add modifier" windows forever.