I'll also be checking out MEL F lounge for the first time. Heading to PER, just happened to find a J award seat on QF9, so booked that the moment I saw it. Otherwise, I've got no plans to travel overseas with QF.
Just hope they don't swap you to a purely dom 737.
I did the J and F lounge "tours" while a QF FF flying EK to AKL, pre covid.
Of course the MEL QFi F lounge was the best, no real runway views, but at least with apron views, and also natural light.
One thing I liked was the no touch doors going to the loos, from the lounge, they are closed, but as you approach, they automatically open to you by sensors!
+++.
The J lounge is the basement one, like a dungeon!
These 2 are worth a visit, even if just once in your life.
Both of the QFi J and F louges, are under gate 10 or thereabouts, ie, far from gate 1/2 where the 737s to close by QFi destos are.
F lounge is around gate 10/11/12, go up the escalators.
You will then have to come down again to board your QFi flight, as there is no access to the plane directly from the lounge, so you have to board with the masses, ... hopefully priority boarding will be enforced.