EET sure is a thing, but a) it's a bit of a pain in the butt to add extra variablesPlease, don't go there.
As it is, your mod would probably lead to ToB proceding with the chapter number of end-SoA and therefore two of my mods would bug out, and not only in EET but in all BGII games. Making this script block compatible is really no problem.
The rest of your post I didn't understand how it is related to this discussion (which it doesn't have to be, I just didn't get what you were trying to say.)