Blood Elves and Dwarves gain access to Heritage armor as part of 8.1, as well, without a prolonged quest line, though they’ll need to be exalted through Silvermoon and Ironforge, respectively, in order to receive it. A Warfront called The Battle for Darkshore focuses on the struggle between Night Elves and the Forsaken. During the Warfront, you’ll be able to transform your character with temporary abilities, and when your faction controls either the Darkshore or Arathi Highlands, you’ll gain access to world quests.
While leveling, try to make use of the new Battle of Azeroth experience gem, Insightful Rubellite, which gives you +5% experience. Equipping one of these requires a socket in your gear, so try to hold on to a piece of Legion gear with a socket or acquire one of the Legion Legendary rings since every class has one. Each of the rings includes a socket. You can acquire one of these rings rather easily by doing World Quests in Legion zones and acquiring 1,000 Wakening Essences that can be used to purchase a legendary ring in the Legion version of Dalaran.
For reference, my previous best time abusing Method-0 in 7.3.5 was 32.4 hours(as show in the old thread). A difference of just over 8 hours; which isn't all that bad, all things considered. And I believe I made several errors along the way, which could be cleaned up in future runs. I believe that that gap could be significantly closed by using a monk's bonus, but I hate playing monk...so...yeah. YMMV