I only hit the back half because I can't run it fast enough to hit reset cap anyway so why not target the highest rates? Flameweavers have the highest drop for PoD and there's five or six of them per run. I make them my main goal along with the dwarf boss and Grimlok. Highest drop for Bushmaster is off is the Shadowcaster dwarfs near the boss too (all rates are from wowhead). Helm of the Deep dropped off one of his adds for me as well.
There are some locked chest locations including by the enchanter lady that could be worth targetting, but I really don't know how chest loot tables work and haven't found much info on them.