In our latest version we have implemented an example for RadDataForm in our Progress Telerik UI for Xamarin Samples app where make some adjustments to the default editors. Specifically for Android you can see how it should be implemented(provide custom layouts through xml files). In UWP, you should create an editor which implements the ITypeEditor interface, while in iOS your editor should implement TKDataFormEditor.
Please, let me know if anything unexpected arises.
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