I'm not sure how Molten Tungsten handles it's modded-compat recipes, wether they're dynamic or not (I assume they are because I have a crapload of random compatible mods in there) nor how they do the recipe spriting but I wouldn't be all too surprised if they're all procedurally generated, considering some of the wacky stuff in there.
Feel free to take your time on it, if you want I can try to weave in a bit of 'looking into it' during my exam season, but I have no experience with lua at all so no promises