Yes, exactly. One of the principles of Prodigy datasets is that they're append-only and that individual records are immutable. This lets you always reconstruct a given annotation and what the annotator saw and labelled.
Not at the moment, no! The manual image annotation UI is still fairly new and we first wanted to focus on the basics and quick/rough annotation features and see how precise we need to make the annotation workflow to cover the different use cases.
From your experience, what's more common: wrong sizing (e.g. box is too small or too large) or wrong positioning? Or both?