You have to show the connections for the DONEx routing. I haven't bothered to check the current timetable for operating routes, but you are booking something like AKL-ADL-BNE-MNL-HKG-LHR-DUB-LHR-ORD-LAS-ORD-LEX-DFW-FLL/TPA-DFW-LAX-BNE-AKL which comes to 17 sectors with 3 left out of the 20 limit. LHR-DUB-LHR is very cheap and doesn't have any D service, so might be better to buy that as a separate ticket, and use the 2 sectors for something nice (like LHR-DXB-LHR).