FF4 assets aplenty, was there a hack?

I'm more interested in the idea of implementing Twincast (or Twin) in the Final Fantasy VI engine. madsiur came up with a workable idea  based on how this status works in Final Fantasy IV, but I worry that there would need to be a horribly extensive code rewrite of the entire battle engine, given that the battle system itself does not support simultaneous actions. Maybe creating battle events that would be triggered upon the command would be a more suitable solution? That will also lead the way for Bands/combination attacks as was mentioned long ago for which Catone provided some ideas on how to implement.

I have nowhere near enough knowledge to even begin to attempt something like this, but I like to daydream.