I concur with this. As an SG, I recently flew QF1 and QF2 in J SYD-DXB-SYD, and connected in DXB with EK1 and EK30 to and from LHR (with me on both via a QF codeshare), but flying in Y. Both meant lengthy but not unpleasant waits of approx 5 hours in the EK business lounge in DXB.
On EK1 I was given an exit row seat, and a fast track card. Fast track card with EK30 (although I didn't use it), and because there were few pax, I was given the middle row of four seats to myself in Y. CSM greeted me both times. I get that as an afterthought, occasionally, when flying J on QF. When I explained to a crew member on QF2 what I had done with my flight home, (Y from LHR-DXB, J from DXB-SYD so I could get a decent night's sleep before a full Sydney day) he looked most disapproving. What's it to him?! Fair dinkum.