Thank you to Argilli Marco (IU4HMY) for writing in and sharing with us his Python application called "SDR# Frequency Manager 1.0.1" for managing frequency lists in SDR#. SDR# is a popular free SDR program commonly used with RTL-SDR and Airspy dongles. Argilli writes:

SDR# Frequency Manager is a Python application designed to simplify the management and editing of frequency lists used by SDR#. The software allows you to open, edit, and save SDR# XML frequency files in a clear and structured interface.

The application is free but closed source and available on his website.

SDR# Frequency Manager Python Application