Virgin Australia sent out an email over the weekend announcing that upgrades are now allowed on domestic flights even from non-flex type fares.
Previously only full’ish flex fares were allowed to upgrade domestically and still for medium and long-haul international flights where lower fares have no upgrade eligibility.
You can access Virgin Australia’s web page for upgrade procedures here.
Up to 1,200 miles the upgrades from saver fares is about double and from longer routes up to triple compared to flex fares.
Conclusion
It is always good to have more options to upgrade flights, but I would have rather seen an option to do this request online rather than having to call service center.