If you run to the (right for Kurzicks, left for Luxons) as soon as you load into the map, you'll find a guard post manned by enemy archers just outside your base. These can be fairly easily killed by ranged attacks or hexes. Any N/x or x/N can then use Necrotic Traversal or Consume Corpse to teleport into the main portion of the arena well before the match starts. This in turn allows them to start claiming mines before the match starts, which is a huge advantage if the teams are even remotely even (not uncommon for them to not be due to leechers & leavers having discovered the Jade Quarry as well

I used to really enjoy the Jade Quarry during the FPE and right after Factions came out. Hopefully ANet will fix this exploit so I and others can enjoy it again.