The description said something about exiting out the back, then flying
through the gaggles in the start cylinder. I don't understand this
because if you did this then by definition you pass through the start
cylinder again and then have a restart on the 2nd exit right?

On a strong day the pre-start gaggles may be much higher than the
maximum start height. It would in theory be possible to exit the
rear, perhaps by climbing through the top adjacent to the rear of the
cylinder then bump pre-start gaggles for approx 10 miles without
descending into the top of the cylinder.

Andy

It is possible to have the start cylinder height above the expected
top of the lift (or cloudbase) for the day. For the most part this
worked extremely well at this years sports nats. The problem was on
the blue days when, as the thermal weakened at the top, the highest
gliders would begin to sink back down, while lower gliders would still
slowly be climbing, ending with close to 20 gliders withing 200ft of
each other. Of course, this could also happen with a start cylinder
of limited height as pilots use spoilers to keep below the top. It
also is probably not practical in the West - 18000ft of free altitude
would make for some impressive speeds, however.

Has the "start arc" been seriously considered? This is a start line
that arcs towards the turnpoints at each such that the distance to the
center of the first turn is the same no matter where you start. It
would still be advantageous to start at the upwind part of the arc,
but you wouldn't be able to get an extra ~5mi on top of that by going
through the side of a cylinder. This is somewhat more complex to set
up, but most modern flight computers have been programmed to support
it and I know its been used in Europe, although have no idea how
successful it was.

2C