After the QF FF shake up in Mid 2019 the points cost to fly to the UK/EU on any of the partners will be 318K points which is also the cap for the OW rewards if you just use OW carriers. Flying CX/ JL may use a few more points but the taxes are less.
I assume you are searching for 1 PAX, it is known that QR seems to only offer x1 J to QFF ex AU but more if going through other locations e.g. KUL, HKG. As a follow on from above as points will cap an extra flight may be required if someones wants to include QR.
At present I am looking to book flights AU-UK/EU rtn in 2022, I am not concerned which carrier or whatever obscure route I may have to use there or back, as points cap at 318K and milage will not be issue. What is important is getting to the UK via a green zone and getting back to ADL as the first AU entry point, MH or SQ seems to be the best options.