Is there a way to setup v4 to utilize CNAME mapping

It would be great if there was a quick and painless way to have CNAME mapping with EE. I would love to be able to setup a site on a sub-domain for development and simply be able to point a CNAME at my sub-domain and have EE accept that URL and present the correct site.

An example of what I mean can be seen here:

There doesn’t seem to be a quick easy way to update a domain on a site without doing a backup, setting up a new server, and moving the backup over. That just seems like overkill for developers. It would be nice to have an EE command to update/change your domain to the main domain after a website is ready for release but another option would be the ability to point a CNAME record at an existing domain and have it work as expected.