I've tried flashing the Giant B firmware to an X10 and running the Giant B image on the Pi but no luck converting an X10 to GB or using that firmware image to overclock (so far).

Interesting that the controller boards are the same, but not surprising. I can't find the difference between those two STM model numbers anywhere online. Could the last couple lines just be batch numbers?

I DID take the heatsink off an X10 and the model number on the asic is this:

[Baikal Logo]
BK177280
ND33U

I'd upload a picture, but the chips are too small for my potato camera.