  In this paper we determine the interaction of diagonal defect clusters in
regions of an Aztec rectangle that scale to arbitrary points on its symmetry
axis (in earlier work we treated the case when this point was the center of the
scaled Aztec rectangle). We use the resulting formulas to determine the
asymptotics of the correlation of defects that are macroscopically separated
from one another and feel the influence of the boundary. In several of the
treated situations this seems not to be accomplishable by previous methods. Our
applications include the case of two long neutral strings, which turn out to
interact by an analog of the Casimir force, two families of neutral doublets
that turn out to interact completely independently of one another, a neutral
doublet and a very long neutral string, a general collection of macroscopically
separated monomer and separation defects, and the case of long strings
consisting of consecutive monomers.
