I believe that the G3 color and mono use the ICX419AKL and ICX419ALL, respectively. They have the sample pixel layout since they're the same chip (just one has a color filter array on it).
I'm assuming that you're able to capture an image in orion capture studio and it looks fine, right? Any chance you could get a wireshark dump while using the indi driver?
I've compared the wireshark dump for the mono and color G3 cameras and don't see any obvious differences in the image download. I think you might be right about command 20 being the way to distinguish color vs mono. As it turns out, VID/PID 0x07ee/0x0501 is the identifier for the Mammut Lyuba L429 camera, so I can fix my guess. You're also right about the geometry of the pixels being of by 1nm. That wouldn't cause the crash, but it should still be fixed.