So, this is actually a bug I was expecting to run into, but it's good to have confirmation, and it should be relatively easy to fix.
In our PCMs, since Dancing Mad 4 is a short intro to Dancing Mad 5, we have Dancing Mad 4 and 5 combined in the Dancing Mad 4 track spot. Due to this, when you reach the last part of the Kefka battle, it plays the first 10 seconds or so of the PCM music and then, upon not finding Dancing Mad 5, switches to SPC. This needs a special case for the track detection where if it detetcts Dancing Mad 5 as the track to load, it bypasses all normal code and silences the SPC and returns. Shouldn't be too difficult or be too traumatic to the codebase, and thus it's marked for alpha