From elsewhere (I'll have to look it up) and from memory, I recall that certain test aircraft have 'other switches' that allow certain functions to be switched off or changed in flight - for test purposes. Earlier I was referring to ordinary production aircraft in which I understand there is no option but to have auto throttle. Perhaps that can be switched off in production aircraft also? I'll stress again my sources are public only and it arrives in dribs and drabs. Do you get that? Go figure.