Can you develop a normal (non open source) apps using Qt/Python? For line of business apps users are not supposed to have access to source code etc. Also, do you have to use QML, did you use QML. At first glance that wasn't so appealing.
You don't need to use Qml at all and can use QtWidgets instead which is just their traditional toolkit, or you can combine both. I tried Qml for parts of the UI and it's fairly straight forward.
I think QtCreator supports python now so if you want a complete IDE with graphical tools that works well, I just used my normal editor.
If you use standalone mode (not onefile) then all the Qt DLLs and pyd files (which are basically also DLLs) are left separate, which lets you satisfy the LGPL.
Edit: The above is about deploying your app. For developing your app, feel free to use whatever flavour of the month pip wrapper you want (personally I'm still happy with vanilla virtualenv). You can assemble widgets and layouts into forms either using code or using UI files created in Qt Designer, just as in C++. I've not tried using QML.