  The asymptotic analysis of Bergman kernels with respect to exponentially
varying measures near emergent interfaces has attracted recent attention. Such
interfaces typically occur when the associated limiting Bergman density
function vanishes on a portion of the plane, the off-spectral region. This type
of behaviour is observed when the metric is negatively curved somewhere, or
when we study partial Bergman kernels in the context of positively curved
metrics. In this work, we cover these two situations in a unified way, for
exponentially varying planar measures on the complex plane. We obtain uniform
asymptotic expansions of root functions, which are essentially normalized
partial Bergman kernels at an off-spectral point, valid in the entire
off-spectral component and protruding into the spectrum as well, which allows
us to show error function transition behaviour of the original kernel along the
interface. In contrast, previous work on asymptotic expansions of Bergman
kernels is typically local, and valid only in the bulk region of the spectrum.
