Thanks. You’ve put your finger on the hard part. From the outside you can’t tell a stalled runner from a slow one, so the Preparer doesn’t try to guess. A claim that has gone quiet past its window gets flagged, just like an overlap does. Someone who can see the runner then decides to release the claim or leave it alone. Auto-killing would be fine if a wrong kill cost nothing, but it costs you half-finished work and sometimes a second agent starting the same job, which is the problem the post is about. A heartbeat from the runner would narrow the window, but someone still has to decide.