Unfortunately for many modern cars that may make it run less efficiently and clean and have a rough start every time you do it for 30 minutes or more because many sensors are trained on-the-fly from a running vehicle and then the correct calibrator sensor values are then stored in volatile memory which is lost upon power loss.

I use to disconnect batteries all the time when fixing vehicles, but the last decade ive been avoiding it unless I have to because of how poorly new cars run afterwards. And people get really angry when you fix something on their vehicle and then go to drive it later and it hard starts and feels and performs worse than ever. Telling them to "just drive for 30 minutes and then restart your car again and hopefully it goes away" doesn't make people happy or confident in your fix, nor does it make diagnosing issues after replacing a suspected faulty module or sensor easier when it sounds and performs like trash for a long while afterwards.

Modern cars sometimes have telematic units running off dedicated lithium ion batteries, so killing main battery might not do anything