@arc123 as per HFA website po, hindi po kasama sa eligible qualification ang diploma and certs:
Eligible qualifications
For the purposes of applying for a subclass 485 visa under the Post-Study Work stream, only study that results in the conferral of an eligible degree level qualification will be considered. An eligible degree level qualification is a:
Bachelor degree
Bachelor (honours) degree
Masters by coursework degree
Masters (extended) degree
Masters by research degree
Doctoral degree
Try niyo po iyong explore iyong graduate skilled stream ng Temporary graduate visa:
https://www.homeaffairs.gov.au/trav/visa-1/485-?modal=/visas/supporting/Pages/485/requirements-graduate-work-stream.aspx