Unless I have made an error it appears that MAXIMUM_EDGE_CALC_LENGTH is not implemented as the below snippet removes 0 faces.
str_factory = """FACTORY_DEF * SurfaceModelFactory \
FACTORY_NAME SurfaceModelFactoryTest \
INPUT POINTS FEATURE_TYPE * \
TOLERANCE 0.0 \
MAXIMUM_EDGE_CALC_LENGTH 1.0 \
INTERPOLATION_TYPE AUTO \
OUTPUT TIN_SURFACE FEATURE_TYPE tin_surface
"""
pipeline = fmeobjects.FMEFactoryPipeline('TestFactory')
pipeline.addFactory(str_factory)
pipeline.processFeature(feature)
pipeline.allDone()
new_feature = pipeline.getOutputFeature()
print(f'Faces removed: {new_feature.getGeometry().numParts() - feature.getGeometry().numParts()}')