GH for sure allows commentary on individual commits (e.g. <https://github.com/torvalds/linux/commit/23816724fdbd47c28bc998866fd7bc5ad9f0e535#all_commit_comments

GH for sure allows commentary on individual commits (e.g. <https://github.com/torvalds/linux/commit/23816724fdbd47c28bc998866fd7bc5ad9f0e535#all_commit_comments https://github.com/torvalds/linux/commit/23816724fdbd47c28bc...>) but they do not automatically roll up to the top-level PR view (since, how would that work with cherry-picks: it shows up in every PR? what if, as is more likely, the line were superseded in a subsequent commit?)