hmm... that's pretty curious, avaquizzer (and, welcome!).
Yep, it looks like each of those maps are on the list of those that precede index oddities.
In order to determine from the index above which map has the "wrong" amount of treasures accounted for, you would subtract 2 from its map index - one because the treasure index references the amount of treasures from the previous map, and one because Pinkpuff started counting at 001 instead of 000.
The others are inaccessible maps (backgrounds, foregrounds, etc.), with the exception of I believe one save point room (perhaps there are a few undiscovered hidden treasures?).
Each is also located "within" a trigger point, it seems (so approaching the trigger point like a chest yields the treasure, instead of standing on it). I'd be willing to bet the parameters of the treasures collected match those of the teleport or event call.
Most likely though, these hidden treasures are an unintentional byproduct of the index oddities.
We have EVEN MORE themes now, but some old ones are gone...
Topic: Developing FF4kster: a comprehensive editor for FF4 (Read 273841 times)