What is the recommended SSL/TLS encryption mode in Cloudflare when using Workers, and why?

The recommended mode is 'Full (strict)'. This ensures Cloudflare validates the SSL certificate presented by your origin server, providing the highest level of security. 'Flexible' mode is generally discouraged as it doesn't encrypt the connection between Cloudflare and your origin, potentially exposing data. 'Full' without strict validation is a compromise, but 'Full (strict)' is preferred.