This is the warning from Noco when using battery repair mode.

NOTE: USE THIS MODE WITH CARE. THIS MODE IS FOR 12-VOLT LEAD-ACID BATTERIES ONLY. THIS MODE USES A HIGH CHARGING VOLTAGE AND MAY CAUSE SOME WATER LOSS IN WET (FLOODED) CELL BATTERIES. BE ADVISED, SOME BATTERIES AND ELECTRONICS MAY BE SENSITIVE TO HIGH CHARGING VOLTAGES. TO MINIMIZE RISKS TO ELECTRONICS, DISCONNECT THE BATTERY BEFORE USING THIS MODE.
Considering how many computers and other electronics a typical vehicle has onboard nowadays and how much each can fetch you if and when they get damaged, I personally wouldn't risk it. But it's you're car so it's really up to you if you think the odds are with you.