zee944 said:

Logically if you time stretch a piece of sound that has distinct effects in it, those effects won't be at their original timecode, so won't be in sync anymore. Stretching make no sense in this case, as the same time you solve a problem, you create another one. In a different case, when the piece you want to time stretch is only an indistinct hum with no recognizable sounds, you could say the stretching won't be noticable. But if the piece is so monotonous why would you need stretching? You could just copy-paste instead....

Thanks for taking the time to explain that in detail.