The document specifically mentions Apple’s own leather cases but states the issue could occur with third-party cases too.
Other interesting information pulled from the support document includes that the new MagSafe charger doesn’t need a 20W USB-C adapter. It requires a minimum of at least 12W but won’t charge the device as fast. To be clear, even when you’re using a 20W adapter, the MagSafe charger is still only delivering 15W to the iPhone 12 since inductive charging is less powerful.
Apple also says to remove credit cards, passports and any item with a magnetic strip or RFID chip in it before attaching the MagSafe charger to the rear of the iPhone 12. The charger can also limit the charging to 80 percent if the battery ends up getting too warm during the charging process. As expected, you also can’t charge wirelessly and when connected to a power adapter at the same time.
You can find the full support document at this link.
Apple’s iPhone 12 series and all future iPhones no longer include EarPods or a charging brick in the box. While MagSafe is an interesting, surprisingly solid solution to some of Qi wireless charging’s most significant issues, including properly aligning a device on a charging pad, the accessory costs $55 in Canada.
On top of that cost, most people will also likely need to buy a $25 20W USB-C Power adapter given the cable that comes with the MagSafe charger is USB-C.
Though the case is plastic, I’ve been using a MagSafe charger with the iPhone 12 Pro and a super-thin Totallee case for the last week and haven’t noticed any marks on its rear.