In custom passthrough mode (and IIRC fixed passthrough), connected to a Wii over component, randomly when I power on the GBS and ESP, the GBS-C will fail to initialize and display an image. When I connected to the ESP over serial after the fact, it did not respond to serial commands. I do not know what went wrong during the boot process, as I did not have a USB serial console connected.

I'll have to get a boot log capture before debugging further. I tried plugging in the GBS at various points during Wii startup, but could not replicate the issue.