it'd be nice to be able to attach comments to a particular line or group of lines, instead of just an entire patch round. useful generally for more detailed code reviews.
(forgive me if I've missed something, but i did not see support for this in either the UI or the pull lexicons)
potentially related to #328 tangentially, in that this is also extra comment metadata, and relates pretty closely to the concept of a review.
also maybe https://tangled.org/tangled.org/core/issues/294 since it talks about comments attached to other things