So, there's always lp:mad to automate the updates of the review diff, but there are no immediate plans to have Launchpad make a moving diff of both branches. As you can imagine, that can require a lot of heavy computational work if it was done on all launchpad projects.
So, there's always lp:mad to automate the updates of the review diff, but there are no immediate plans to have Launchpad make a moving diff of both branches. As you can imagine, that can require a lot of heavy computational work if it was done on all launchpad projects.