You have to consider why it is doing it. Mazda are obligated under legislation to keep emissions down. This revving is not a “fault” or an “issue”, it is an intentional design function to speed up the efficiency of the catalytic converter. I’ve heard some people say that you can defeat it by putting it in gear! Well done, all that does is extend the warm up and increase harmful emissions. There is no need to fret about it. Leave it alone and let it get on with it.