Followup: while Networkmanager overwrote any 127.0.0.* address, I discovered that it will leave 127.1.1.* (etc.) alone, so I was able to add
127.1.1.1 myhost1.localdomain 127.1.1.2 myhost2.localdomain
etc. and not have it overwritten by NM. Thanks to Mathieu for the suggestion -- there *is* a workaround available now.
Followup: while Networkmanager overwrote any 127.0.0.* address, I discovered that it will leave 127.1.1.* (etc.) alone, so I was able to add
127.1.1.1 myhost1.localdomain
127.1.1.2 myhost2.localdomain
etc. and not have it overwritten by NM. Thanks to Mathieu for the suggestion -- there *is* a workaround available now.