A simple script I made to help me review cherry-picked pull requests where diffs are expected to be similar. It fetches the PRs' diffs using the GitHub API so it works on deleted branches too. It outputs a (cleaned up) diff of the PRs' diffs to highlight any differences.
gh extension install https://github.com/samugi/gh-comprgh compr <PR_1_URL> <PR_2_URL> [-o output.diff]
Diff saved to output.diff