The enchant farming is not too bad, I mainly use default completion bonus to make it faster, plus you gain XP for your toon. Gear farming (shop farming) is probably more time consuming. To succeed in this challenge, the yellow gears need to be heavily optimized.
Like yesterday, with ThrowerYellow, I farmed the Hydra for 1+ hour and I already got all the enchants I need from him (Achilles and Dionysus sets). I also spent 1+ hour to farm the shops for gears and I didn't get any new armor gears (still using most of them from epic Rhodes), only some new ring/amulet.
I'll probably do the main gear shop farming in legendary Rhodes though.
Anyway, this is also an interesting thing about this challenge -- find the best way to optimize your gears. And with yellow gears, there are more ways to optimize them than with using non-restricted gears.