We develop on Avalonia, it provides very limited control set and functionality, and 3rd party libraries/controls do not exist yet. Cross-platform framework requires some time to become mature and create ecosystem around.

Checkout https://GitHub.com/qmlnet/qmlnet

It leverages the entire Qt system with the power of .NET. We use it on embedded medical devices.

And how's it on production? I remember, we considered it, and rejected because the framework visibly far from release. Maybe, we were wrong.