I often have Claude make code walks specifically to present walls of code more sanely, add diagrams, bring in code context outside the diff, etc. This is one manifestation I made but I think there are many ways people are solving this (or roll your own tool!) https://github.com/jeffbaumes/code-walk
This is a great idea. Combine this with a tool that allows you to mark the lines of code you have reviewed and understand, and you're on your way to systematically working through the PR.