I just had another thought listening to a station that is not very clear.

Imagine if you varied the power output and also at the same time had a secondary audio signal of maybe a few hours long and played under the main music
that had dead carrier, noise and crackles and interference. It would sound to the ear that the signal was getting weaker as the noise got louder and crackles more frequent.
This would also give some kind of psychological listening problems as it randomly sounded like the signal was becoming weaker to the tracker, that and power modulation would make it really weird
for them to understand what was going on.

All of these are probably non starters but funny. Quite technically challenging as well.

Anorak listeners would not care about the signal going up and down up and down and all the random, hiss and noise, in fact they would be all the more excited for it.