I have a Porsche 911 Turbo MY2002 and have installed a RESTART9 in it about a year ago. Regarding jump starting, if I ever need it, can I use the factory procedure, which is different from what you have in the manual: Porsche says jump start from the two jump start posts in the engine in the rear (the battery is in the front), the +12 post being directly connected to the alternator, while the mass post is attached directly to the chassis.
Your procedure says remove the +ve cable from the battery and jumpstart to the detached cable, bypassing the battery.
Could I use the Porsche procedure and leave the battery connected to the car or should I always detach the +ve cable from the battery?
The cigarette lighter socket or any other 12V vehicle or boat socket is for charging only, as noted they are not designed for high current input or output. It’s simple to disconnect a terminal while starting and reconnecting once the engine has started. The battery will not blow up but you can shock the cells due to their low internal resistance if connected directly. This is the reason Lithiumax batteries charge so quickly too 👍