What does that mean? How do you access HN through CloudFlare and what do you mean by AWS not supporting TLS1.3? You can certainly run any https server on EC2, including one that supports TLS1.3.
drill news.ycombinator.com @108.162.192.195
Those are CF IP addresses. Before HN switched from M5 to AWS, CF was an alternative way to access HN. echo|openssl s_client -connect 50.112.136.166:443 -tls1_3