Hey there!
I understand that you are working on merge queues/etc. but this really really was a good feature.
Our CI takes about 20 minutes to run and it makes merging a long stack painful: if you merge the first 2 PRs in a 10 PRs stack for instance, the 3rd one will have "merge conflicts" (which aren't really merge conflicts as when you rebase they auto-solve) but won't be auto-rebased by graphite. So you have to do it manually and re-submit.