Hi! At the moment, 10 is hard-coded as the maximum (and a smaller size is used for batch sizes lower than 10). I guess we could expose the history size as a setting as well – however, one thing to consider here is that the history shows the most recent annotations that are still on the client and can be changed. Prodigy sends the answers back in batches, so the larger the history size, the longer it takes until answers are sent back (and the more work you can potentially lose if you don't save).