For me the calculation does complete using your python script, but it takes a long time (~10 minutes maybe). The reason it takes longer to execute the python script is because the VolumeMassProperties calculates much more information than the Volume command.
I’m not familiar with typical run times for the VolumeMassProperties function so I don’t know how odd this case is. Have you tried increasing the tolerance value?
Thanks for testing, it’s indeed a long wait but it will finish in the end.
I have found meanwhile that shrinking the trimmed faces surfaces will greatly reduce calculation time.
I’m probably going to use that as a preparation for processing the breps.