That clarifies things. This proxy will accept HTTPS requests but just forwards them instead of actually proxying them. Its SQUID, so doesn't support SOCKS5. I'll roll out a SOCKS5 proxy on it and retest.
Thanks for the update and sorry for the confusion.
That worked perfectly. Thank you for the clarification. I still pass the proxy info to java in the event that there is something else that requires that info.
Makes sense. Are those passed to minecraftdev.jar or instead of the standard proxy setting for Java? I'm guessing you mean to pass them to the launcher. I'll test when I am back in that environment.
EDIT: Deleted the attachment, showed that there is some SSL man in the middle issuing the certificate.
Tested, confirmed that a socks proxy is required. Not an issue with the software.