Bringing your own trust store to system https libraries is not often supported. Especially when you get into kinds of embedded environments Netflix supports. You also might not have the capability to bring your own TLS library either. If it's a limited environment, you might only get reasonable performance if you use the system ciphers, and they may not be exposed as primitives, and x.509 parsing takes up a lot of code space in the likely event that you've got limitations there too.