Hardly an expert here but..

The problem with a big start is that only a handful get good starts... a handful get fair starts and many get tanked. This situation shifts the results to ... winning the start = the game.

The 505's use the 10th' place boat as a pathfinder boat.
This boat will sail close hauled on port tack starting from the starting area at time = zero. the pathfinder is a rabbit followed by a powerboat or gate boat. At t = zero this boat is racing the course but must continue on Port until released at a set time by the Mark boat or after the last starter has crossed. If released by the gate boat... the Gate boat itself is the rabbit and continues off to the right side of the course until the gate is closed on an agreed upon time.

So...it seems everyone gets a fair shot at a lane going upwind... and you are not screwed by the screwup of someone else on the starting line.

If you take the transom of the gate boat.... You have started at time = zero. (relative to going up wind anywhere on his track up wind)... if you start further back from his transom ... you were a bit late.... you might have clear air.. but you gave up the distance between you and the boat crossing the pathfinder's transom.

The Fleet positions them selves up wind and when the gate opens... they are free to start on starboard... cross the pathfinder and race the course.

In addition... The chaos of calling OCS's is gone. You can't be PMS unless you jump the gun at Time = zero

I must admit... I would like to try it out in a big fleet and see how it works.