So, I've spent some time with the set and it looks fantastic.
One challenge for me, since I am using RPG Maker, was to get the various water and ground tiles configured into viable auto-tiles; is that something you might consider adding later, and/or for future asset packs? I'd kick down a commission towards this, if you have any interest.
I was able to make something decent in GraphicsGale via some cutting/pasting/scaling, but it's not professional quality (some of the transitions look a bit wonky). I can send you my files for reference, but again only if you might want to pursue it.
Regardless, I am looking forward to further asset packs!
I really, really need a FFIV style underground with lava oceans and such... just sayin'.