Follow the BOC instructions. Open fully then back a turn. Besides - if open just a nats, gas passing through a small orifice is likely to freeze up the 'ole. As for being able to turn off quickly in an emergency, the gas bottle connector has a high-flow shutoff anyway. Cheers.
Derb. 2017 Colorado LTZ 4 x 4 Auto. 2014 Southern Star 720 and 1980 Zephette 340. 2 x 100 a/h AGM. 3 x 150w solar. Ctek D250S-Dual controller/MXS15 charger.172L fresh/grey. Diesel heat. RMD8555 fridge.