I don't mind rebasing, so that's not really an issue.

The problem I sometimes have is when I queue up 4 or 5 PRs in the afternoon and expect someone to take a look in the morning.

The diff of A into master looks OK, but then the diff of B looks like AB, and the diff of C looks like ABC - each PR has changes that will have already been merged once earlier PRs have been accepted.

My way around it was to raise E as a PR into D, raise D as a PR into C, etc. Then once approved, I change their destinations back to master for the actual merges.

It really confuses reviewers though, even though it's meant to make it so they only see the appropriate changes.