On making CFAD over a specific area/domain

I’m currently working on generating a CFAD (Contoured Frequency by Altitude Diagram) using Py-ART over a specific geographic domain, similar to this visualization of Chen et al. (2019) in Figure 6. I’ve already written an initial Python script that attempts to process and visualize the CFAD, but the output doesn’t appear to be correct or meaningful.

May I kindly ask if someone could provide a working example or correct code that shows how to properly ‘subset’ radar data (CFRadial) over a defined lat-lon domain to generate a CFAD?

I’m happy to share my code snippet and sample data for this case.

Code: Jupyter Notebook

Sample Data: CFRadial Data