I don´t remember if it is in every time that one reward are 5 extra moves. If you get that reward. As it is today the 5 extra moves automatic starts in next level you play.
My suggestion are that it is made that you can choose when you will use it. So at the end of a level that you are failing that it comes up a popup that ask if you want to use your extra moves. Then you can accept it and contuine to play if you think you will pass. Or you can say no if you think that it don´t will help on just that time.
As it is today it is not always that you need the 5 extra moves at just that level. So better if you can choose.
Hope you understand.