I have not yet gotten a full pwn on the Uni, but I can decompile the flash dump from the pix, and the memory map in ghidra shows where the assets are. On the Sonix microprocessor version, the assets are fixed at 0x200000 on flash
binwalk with every possible flag I could find useful in the documentation is completely useless. I tried writing a magic bytes file, but I dont think I did it right. Still, what I do have is in Pix directory.
Zip of my tama folder with all my notes and work https://sias.space/s/P65mRCfnRPXgrfp