Toolchain team builds test images for chromeos and many times the test image is broken. In that case, the only option is to flash another image via usb.

But many times, usb flash can't be done since it has to be explictly enabled via command 'enable_dev_usb_boot' and sometimes the broken image does not let us do that. This creates a lot of headache since we have to use recovery images etc. and sometimes even recovery image via usb is also not very reliable. 
It would be great to enable usb boot automatically when test image boots. 
if not as default, maybe through an option in build image?