As I said in an other feature request, I am using musescore in educational enviroment.
To create a accidental works now in this order.
Key with the letter of the pitch, and you hear the pitch. Then using the arrow and hearing the correct/alternated pitch.
Of educational reason (f.e. train musical imagination) would be this order better. Press a key (# or -) than the key with the letter of the pitch, than someone hear the correct pitch.