Stand down is probably a bit better than furlough because at least people are accruing AL and LSL along the way. Not sure if furlough has that benefit.
That said, I don’t reckon stand down was ever intended for this sort of ongoing situation, or a situation where parts of the company have work and other parts of the company have zero.
I suspect stand downs on the A380 is going to be a sad fact of life whilst other LH fleets still have rolling stand downs (due to international border closures). My personal opinion is that once borders are open and other LH fleets are back flying then the lack of A380 flying looks more like a commercial decision and stand down becomes very hard to justify. I suspect QF know this and are trying to work out how they solve that problem in about 12 months time.