I managed to select seats on RJ.com but had to select one pax then close the page down, reopen it, log back into the booking and select the seat for the other pax. A faff but it does show the correct seats on QR's site. Cant book Q suites as detailed above.

This approach worked for125 ticket stock and 157 using BA gold status to book seats including bronze and blue members on the same PNR.