I agree with pushing the button just once.(burnout)
However, if you like the "confirm note", perhaps you can add a stebel nautilus air horn like the Miata owners do. I just added one to the Miata, they are 35-40$, and it is a self contained compressor/dual horn unit that is nice, loud and commanding when you need to lay on the horn. If I am not mistaken, when the air horn tries to reproduce the short "confirm note", you will just get a muted note.
I like it so much, that I plan on adding one to the Mazda5.
In the Miata, if I used the horn, I would not get any reaction from the other driver as they were runnning me over. With the new air horn, I get an immediate reaction: a steering correction, a wave, or a finger.(headbang)