For example lets say I killed 4 separate spiders as I went along. The 4th one respawned instantly forcing me to kill it again while the 3 previous spiders still had not respawned.
I am all for dynamically adjusting spawn times based on the number of people in the zone. But it should have better bounds checking. Instead of allowing a spawn time of 0 to ever be set at least give the players enough time to move away from the spot. It should also have less variance to avoid those cases where you kill everything in sight and the last mob standing just decided to become immortal and respawn over and over and over and over while all of his friends stay laying face down in the dirt.
meh either way its pretty minor. TB questing is fine minus occasionally getting graveyard camped by a group of alliance mad about losing again.