The text just stays there and never fades out, long after you toggle it on or off.
I think it would be best if it faded out like when you select an item on your hotbar.
If you didn't know the hotkey already, it's confusing to see that text.

Commit: 2e715ef
Text will fade out after a second (Can be disabled in the config. Default: true)
[In the next version]