(3DS) A texture that displays on the model but can't be found in the texture list

[CHEMI6DER]

The main texture for the majority of the stage (including the floor and the large Fawful emblem in the center) is missing from the texture list, can't be found on its own, and yet is clearly displayed on the "model" in the viewer. I need to find a way to extract that texture. To see what I'm talking about, see below: You can see it in the viewer, but below the texture list is a screenshot of the File Explorer with all the extractable textures, it's not included with them. If anyone's familiar with a similar issue viewing 3DS models in SPICA (or Ohana3DS, as the texture list I get with that program also doesn't include it) is there any way to get that texture?

Hi. I'm also currently poking around the files of this game. It's very strange that it doesn't show up at all. I've checked both original Ohana, Ohana-Rebirth and SPICA and they all don't list the texture at all. Even Kukkii doesn't list it...Thought Ohana's Texture Info readout is interesting...maybe it's embedded in a shader?

And also regarding one of your other threads: PTX is probably a container of some sort because one of the ptx files I inspected under a hex editor had not only a BCH but also a BTI file inside of it. For many cases just stripping away everything before BCH magic will just work fine to extract the bch.
Also, do you know how _CA_INFO_ entries are structured? I found out that the first 16 bytes(maybe first 12 bytes, IDK as I haven't researched more yet) list texture filenames in C-style null terminated string format. And then there's data which probably contains stuff like texture encoding, dimensions, tile size and all other texture related stuff. I didn't manage to understand it, but I was able to get something resembling a properly decoded texture by manually playing around with Kukkii's RAW Import menu. 
On the two images below you can roughly make out that it's Midbus.


BTW, how did you extract bg4 archives? The problem is that no tools whatsoever want to open the extracted BCH files and I think it's because of the compression. I tried using MSBT Editor Reloaded but it extracts only compressed files and doesn't have a decompression routine, neither does it's source mention which compression it uses.
Edit: found that one QuickBMS script that extracts bg4 properly. Turns out the compression is BLZ. Gonna put a link to it here in case someone searching for this needs it: link