Regarding deciding between AONE* and DONE*, bear in mind that availability of A inventory seems to be far more restricted than D.
I'm currently researching a DONE4 (nrt-hkg-jfk-lax-sjo-lax-ord-sju-jfk-scl-puq//ush-bue-mad-mow-amm-mct-lhr-hkg-del-nrt totals "only" 58344 miles) and while checking availability for some dates next year, there is loads of D inventory on every segment (other than a couple of flights with Y cabin only). However, many of the flights that have F, are showing A0, and I would be struggling to actually book this in A.
Especially if you anticipate date changes as the trip progresses, it could be much harder to get A than D.

Happy Travels.