I believe things have changed, quite significantly. For a year or more? QF is no longer the handling agent for FJ in Australia, and I have spoken to QF staff in both Flounge and J lounge who are finding that the working relationship with FJ is not very collegial, to do with all kinds of things like baggage interlining, issuing of boarding passes for connecting flights etc. The change resulted in some long-standing FJ staff at Australian airports who were very popular as good people to work with, and who got on well with QF staff, losing their jobs.
Now, if you are ticketed FJ, then you are pretty much on your own as far as QF is concerned, including NO lounge access based on QF or OW status. The only way to get lounge access if you are ticketed FJ is to be a member of Tabua Club, or to be travelling in J, and in each case you will only get into the J lounge, not Flounge.