Keep in mind, external events need a scene to base them on. So you may run into problems if not all objects are the same type and name across all the 80+ scenes.
If all the scenes have the same objects, for example if you’ve created new scenes by duplicating an existing scene, then you could look into using only 1 scene and instead have an external layout for each level,
If you name each level’s external layout incrementally (so “Level1”, “Level2”, Level3"…), you can then store the current level in global variable, and using a “At the beginning of scene” event load the eternal layout. Somethign like:
