I am not sure what clarification you need.
To Qantas you are a Qantas Platinum. To Cathay, AA, BA, MH, Finnair etc you are Oneworld Emerald.
It really cannot be any clearer.
It is clear that you believe that but you saying that 100 times does not make it so. If you can point me to the part of Qantas' or Oneworld's website that states this I am happy to stand corrected.
Let me clarify what I can see off the websites:
1. https://www.qantas.com/fflyer/dyn/flying/tier-benefits#benefits-of-platinum "Benefits of oneworld Emerald status
With oneworld Emerald status, when you fly oneworld you'll enjoy privileges like preferred seating, priority check-in, and access to over 600 oneworld alliance airline Business and First lounges. "
- i.e. QF Platinum status confers OW Emerald Status
2. https://www.oneworld.com/ffp/lounge-access
"Members of oneworld airline frequent flyer programmes with the equivalent of oneworld Emerald or Sapphire tier status can use lounges offered by oneworld airlines when departing on any flight marketed and operated by any oneworld member airline"
- i.e. OW Emerald status confers at ANY OW lounge access rights when travelling on ANY OW airline
Therefore QF plat members have OW emerald status that they can use when travelling on any OW airline (Qantas) at any OW lounge (Qantas).
Somewhere along the lines you all must have seen a clause that excludes home airline access to home lounges. I will be most grateful if you could direct me to this clause. Clearly my English ability is insufficient to find it myself, as many are offering me free English lessons in recent posts.