You are right, the setting are min., medium, and max. traction control.
If you hold it 2 sec. the TC will be completly OFF.
Honda does not give a % of spin allowd for each setting.
They only say it measure the difference in rotation between front and rear wheel.
Wich setting you choose depends on how much you wanna play.
In all tree settings the TC comes in smooth and correctly.
Off road : minimum or OFF
Wet road : Full or medium
If you are in deep mud, turn it OFF to keep traction even when to front wheel
is standing still.
Or when you want to wheelie.
Every time you switch IGN. it will start in FULL TC