If he is savvy enough to notice a distinction, by the channel, I am confident he can work the toggle button. The other option is to use the OEM remote to find out what code set the device is using, then fire all possible commands within that code set to see if one of them is works for what you want. I am not aware of discrete zoom modes for Sony TV's, but then I am a single user. I happen to use Sony daily, but that is merely an aside. So the exercise above my be totally useless to do. Who knows if the Sony sets even have that option.