  Signature change has been identified as a generic consequence of holonomy
modifications in spherically symmetric models of loop quantum gravity with real
connections, which includes modified Schwarzschild solutions. Here, this result
is extended to 2-dimensional dilaton models and to different choices of
canonical variables, including in particular the
Callan-Giddings-Harvey-Strominger (CGHS) solution. New obstructions are found
to coupling matter and to including operator-ordering effects in an
anomaly-free manner.
