Jim wrote:
out to me that even with the string in the middle, in a steep turn the
inside wing is flying at a higher angle of attack than is the outer
wing.

This is so, in theory, for a descending turn, and the other way around
for a climbing turn. In power flying we are taught that from a descending
turn you are more likely to spin in the direction of the turn and in the
opposite direction from a climbing turn. All this is based on there
being a certain amount of rotation around the longitudinal axis in
a descending/climbing turn.

If a stall is induced in such a steep turn the inside wing is
likely to stall before the outside wing and thus will have higher drag
than the outer wing and the glider will likely fall off over the
inside wing. If confusion or inadequate skill or distraction get in
the way of an immediate recovery the higher drag of the inside,
falling wing may initiate an autorotation and possible spin entry.

Does this seem like a real possibility?

A glider is of course always descending, in relation to the surrounding
air mass, thus creating the effect described, but at the glide angles
of modern gliders, as opposed to power planes, even in a steep turn,
I'd expect the effect to be very small, perhaps too small to make any
real difference (?), It would be interesting to hear whether anyone
has been able to observe this in practice.

And as somebody already pointed out somewhere in the spinning
thread, in a steepish turn you can often (depending on the type
of glider) fly with the stick on the back stop without ever
slowing down to stalling speed, making it next to impossible
to provoke this type of spin, even if possible in theory.

CV