I am a QA automation analyst responsible for testing a multi-platform online banking application. For our automation testing we use RubyMine suite with Gherkin/Cucumber, Rub
Try https://github.com/lightbody/browsermob-proxy
I dont know if it can satisfy your requirement as I am no way a network expert, I do use browsermob-proxy extensively to capture network request along with selenium and there is a method to blacklist certain request
https://browsermob-proxy-py.readthedocs.io/en/stable/client.html#browsermobproxy.Client.blacklist
How to disable loading external urls on seleniumlibrary/robotframework