The 'rate' property is ignored when playing back an MP3 file.
The rate is taken into account when playing back a WAV file.

To reproduce, use the Monkey Tester
https://github.com/andy-goryachev-oracle/MonkeyTest
which allows the user to select the input file and set the properties manually before clicking the "Play" button.

(I did not try other properties, please check)

I can see two possible outcomes:

1. This is a real bug, that is the native media player JavaFX uses does allow for setting these properties but it's never done.
2. Support for other properties might depend on the source file format. We might decide to update the docs to say that.