Are you sure this isn't a ploy to see how many LetsEncrypt certificates you can collect?
The spec for DNS really should get expanded to allow CNAME records for the root domain
Since CNAME is not specific to A or AAAA records, a CNAME record on the root domain would also override your SOA and NS records, which is probably not what you want.
Makes me kinda glad I use Cloudflare, if I ever need to do this, because of their cname flattening