I also just thought that it would be nice to be able to clear the calibration of a controller individually, such as by clicking the Car ID box. This would allow RCS64 to save controller calibration in the same place it normally does, so that controllers do not NEED to be recalibrated before every race, but a driver can choose to do so prior to the race, either by performing the calibration trigger motions (pull 3 times then hold, maybe?), or by clicking the Car ID box. This way, if people don't rotate or change position, they don't need to calibrate the controller, but if someone changes controllers (this happens more than you might think), or if they do rotate but want a "default" controller response (e.g. no calibration), they can clear what's in there.
To be clear, here is how I imagine it to work.
First race, all drivers wish to calibrate their controllers. The option to do so (on the Main page) has been enabled. All Car ID boxes are yellow (to indicate not calibrated for this race). If the Calibration option on the main screen is NOT enabled, then the Car ID boxes have no special coloring. They each pull and release the trigger 3 times, each time causing the Car ID box to flash red. then pull and hold the trigger (red light) until their Car ID box lights up green (calibration complete). Controllers are calibrated, they can choose their tires and press brake to start the race.
Second race, no rotation, but drivers 2 and 5 change controllers. On Pre-Race screen, drivers 1, 3, 4, and 6 do nothing. All Car ID boxes are green to indicate controller calibration complete, but 2 and 5 want to re-calibrate. They pull their triggers and their Car ID box flashes red each time they do, but return to green (not-recalibrated). This prevents accidental clearing if they didn't mean to do so. If the pull/release three times AND pull/hold once, then the calibration is overwritten by the new data, and the Car ID switches to Green from red when the routine is complete.
Third race, drivers have rotated and everyone is in a new lane/Car ID. On the Pre-Race screen, drivers 1-5 all pull/release three times then pull/hold once until their Car ID box switches from red to green. Driver 6 does not wish to calibrate, but does not want the previous calibration, either. The race marshal can click the Car ID box to clear previous calibration, and go with whatever the default is.
Another idea would be to make it so that pulling the trigger fully three times clears out previous calibration, and the final act of pulling and holding the trigger is what saves the new calibration. That would allow the drivers to easily clear, or clear and recalibrate, without needing marshal intervention. A Green Car ID could switch back to Yellow after the three pull/release cycles to indicate that calibration has been cleared.
Just some interface ideas for when you're ready to work on this.