Ha, fair enough!
The Add Spawn is based on a timer for how long you stay in the pool. You might be getting lucky on timers. But honestly you could just ignore clicking people in general and just keep burning him down.
If you get him positioned quickly enough you shouldnt have to really move at all.
In our experience, the add only spawns if you exit the pool to the south/southwest. Have everyone exit to the northeast and it shouldn't spawn.
This should probably be added to the strategy. A number of new raid forces won't have the dps to kill it before breaking their weapons (tanks especially). Maybe add a recommendation to watch main weapon and have second one on hotbar to switch out if trying for first time since this is the PR of SF.
That is good to point out. We never clicked on anyone, we just had people run into the pool hehe. Nice find. Strategy updated!