This is almost exactly what https://github.com/googleapis/gapic-generator-python/ accomplishes: it is a protoc plugin that, given protobuf descriptors, generates client libraries and proto-plus message classes. Try taking a look at that and see if it fits your needs.

So, to answer your question more directly, what you want is very possible, but it falls outside the strict scope of proto-plus and is instead accomplished by other tools.

Thank you, I will give it a try!