Interesting question, here is some information:
First of all, the qmlplugindump tool loads a dynamic library at runtime and searches for properties, methods and signals with the help of the QMetaObject methods. That requires the tool to use a shared runtime library, dumping a static library is not possible. So I don’t think that’s a bug, that’s just a technical restriction.
Back to your topic: What’s the error you’re experiencing with qmlplugindump and V-Play? V-Play ships with stub QML files in the qml/V-Play subdirectory which should be enough for the tool to work.