LetsEncrypt now has an ECC root and intermediates. You have to request the account ID to be included, and after which, the intermediate and root certificates will be ECC. More information here: https://community.letsencrypt.org/t/ecdsa-availability-in-pr...
The alternative you suggest has a longer chain of certificates, and more difficult setup. Using ZeroSSL is way easier with less bytes on the TLS handshake.