I can answer half of that only: the BBC did often run into trouble, to the point that they cite the
*TV command as early as Page 17 of the user guide:
If the picture on your television screen is either too far up or too
far down the screen, you can move the whole display with the command
*TV 255 will move down one line
*TV 254 will move down two lines
*TV 1 will move up one line
*TV 2 will move up two lines
The movements come into effect next time you press BREAK or change mode.
*TV also controls the interlace of the
television display. See chapter 43.
They felt the need to drop that in at the end of the second chapter, 'Commands', which first introduces directly the idea of typing a command in order to get the computer to do something.
Having felt the need to mention that use right up front, they don't bother defining *TV in detail until Page 419.