What screen sizes, devices must we support for iOS 13, 14?

I've been trying to get clarification on device support, but what official sources I've found have been ambiguous.

If making an app for iOS 13/14 (iPhone only, not supporting iPad OS), in terms of app submission rules:

1. What is the smallest screen size that we need to design for and support?

2. Do we need to support the iPod (7th generation)? Or can we elect not to support iPods?

Currently, the smallest compatible iPhone form factor is 4.7". Whereas the iPod is 4".

For business, design and usability reasons, it would be much easier to design for a lower limit of 4.7", rather than the (very restrictive) 4" screens. Is that acceptable with regards to the app store rules?

Thanks for any help.