I have a Blender plug-in that loads in the Daz FBX file and creates the ini file needed by CC3 automagically (you don't alter the FBX file in anyway -- so you don't have to export it out from Blender again, just run it to generate the ini file. It also generates all the folders and maps needed for the "Load All Textures" routine for clothing to work but right now I'm just concentrating on the ini file for your consideration). It works with about 98% of all the Daz figures (there are a few that stump it, but even those it will fill in a few textures -- for the rest it fills in 100% of all the maps available).
Obviously it's a PITA to require folks to install Blender, load in the FBX file, and run my plugin, so what I suggest if you incorporate the code (or at least the idea) into CC3. It's not rocket science -- I just examine the diffuse maps that ARE available in the FBX (I also look at what other maps might be there, but it's usually only the diffuse that exports) and on that basis I locate where the other maps might be and load them in). The only "gotcha" is that it requires that someone have the Daz content directory and the appropriate content installed on their machine -- you couldn't take the FBX file and send it to someone and have them load it in correctly. But it won't choke if that happens -- it just won't create all the maps (so it's the same as you already have for the ini file creation).
I'll put a link to the Dropbox code (which is always changing as I improve it -- it's VERY sloppy coding but I'm an old man who hasn't been in the business for over a decade now) but if you need explanation on how it works or just want more on the concepts I'll be glad to elaborate (I've already made a video showing how it works and posted it on the beta forum, but I can do another one if you'd like where I describe more of the process).