I did some looking into the file format. It's tricky because it doesn't seem to ever declare how many sub-images are in an image, it just determines it by the header length, and the header length is something like n*11+48?+16? and I'm only like 80% sure of those numbers.
I need to find the code in the binary for loading this. I've just been staring at the hex. it seemed simple enough, but the multi-image format is more complex than I thought