  We investigate scenarios in which the low-temperature phase of short-range
spin glasses comprises thermodynamic states which are nontrivial mixtures of
multiple incongruent pure state pairs. We construct a new kind of metastate
supported on Gibbs states whose edge overlap values with a reference state fall
within a specified range. Using this metastate we show that, in any dimension,
the variance of free energy difference fluctuations between pure states within
a single mixed Gibbs state with multiple edge overlap values diverges linearly
with the volume. We discuss some implications of these results.
