And what does he want to use it to do?
Regular Fedora should be perfectly fine. I'd ensure a separate /home partition and a backup for ease of reinstallation if it gets wrecked. Yes, an atomic distro or btrfs snapshots could do that too, but like you mentioned, there are other considerations for atomic distros. And a separate /home partition eases installation of other distros if Fedora doesn't do it for him for some reason.