Then all you would need to do is set all your reaction spells on "ask" ... and you would have full control. People who would like to spend their reactions no matter what on first opourtunity, would set them "on" ... And people who want anything in between would set it also to their prefferences.
That is the beauty of such system, everyone can set it EXACTLY as they want. ^_^
If my comments bother you, there is nothing easier than telling me to stop. I mean ... I won't ... but it's easy to say.