I feel like the DTC mode (just 1 push) is too intrusive for serious use, while the "all off" mode (2 pushes) may be sometimes difficult to handle (especially at high speeds or in narrow tracks).
Something in the middle would be definitely good...
Have you ever heard about this?
http://www.racelogic.co.uk/index.php...action-control
Unfortunately seems to be not easily applicable to post 1999 models