Patrick,
I am well aware of Rule 8-2a, which allows indicating the line of play as long as the indication is removed before the stroke. The breaking down of the rule about indicating line of play into two sections, one on the putting green and the other elsewhere supposes we are talking about the golf course. To inject this to include the golf ball passes by my version of common sense.
One point that I was trying to make was that there is another common point where a ball is not in play, and the player may decide to line his ball up with the "cheater line".
(To digress, congratulations on framing the argument with your title.) We have covered the putting green when a ball
is marked and lifted. We have not covered when a ball is placed on a tee.
If a player positions a teed ball with the 'cheater line' aimed at the line of play, wouldn't they be in equal violation of the rule or its spirit? As you so adroitly pointed out, they would have to remove the indication before the shot.