Paddles are digital. The controller says 0 (off) or 1 (on). The game doesn't have any sensitivity to adjust; it just uses what the controller says. I'm assuming that's what you're referring to.
I have a new wheel for my direct drive, and sometimes I shift two gears at the same time. (I'm fine in manual...) The joysticks may be too long (too much force?) There you go.
look in your player.json for the following line, I have mine at 4; "Repeat Shifts":0, "Repeat Shifts#":"0 = no repeat shift detection, 1 = detect and eliminate accidental repeat shifts within 100ms, 2 = 150ms, 3 = 200ms, 4 = 250ms, 5 = prevent shifting again before previous shift is completed",