Custom QML types are limited to 50

At the moment the number of custom QML types is limited to 50. This limit is arbitrary and far too small for any serious QML development. E.g. I'm currently working on a project where I have more than 60 custom Python QML types, and the project is still under development and growing.

See: http://code.qt.io/cgit/pyside/pyside-setup.git/tree/sources/pyside2/PySide2/QtQml/pysideqmlregistertype.cpp#n59

I suggest fixing the core problem of not being able to create QML types at runtime. Someone already attempted to do this: https://github.com/msorvig/qt-quick-bindings/blob/master/0001-WIP-Support-run-time-QML-type-creation.patch