Any downsides of buying AppleCare+ on the iPhone directly (within the 60 days period, rather than at the Apple Store at the date of purchase)?
I bought the iPhone 13 pro on launch day and I am considering getting it.
No downsides, it’s the same price that in store and it’s very straightforward. The iPhone will run a short diagnostic to be sure that your device is not already broken (especially the screen) and if successful, you will be able to add AppleCare.