Thanks for the feedback, appreciate it!
In general, we used the built-in pipeline, but that was only enabled towards the end of the project.
I think this fog of war system is pipeline-agnostic, although I'm not too sure, still learning about these things. You can find the tutorial we used in the description - uses cameras, render textures and shaders - it felt somewhat straightforward to implement and was actually the first thing implemented after creating an empty project - before anything else.
What are the issues that you are running into?