There is still something missing in our framework. We already have an issue for it. The output might not be very good even if you pass in a ProgressMonitor.
The following code snippet should create a PM for you which you can pass to the write product method.
def createProgressMonitor():
PWPM = jpy.get_type('com.bc.ceres.core.PrintWriterProgressMonitor')
JavaSystem = jpy.get_type('java.lang.System')
monitor = PWPM(JavaSystem.out)
return monitor