Unfortunately, frame index references are usually position based, so if frames get reordered later the object instances can break exactly like you described. Frame tags are helpful for runtime logic and lookups, but in the Editor there often isn’t a built in way to bind an instance directly to a frame tag as a permanent reference. A safer workflow is usually to avoid reordering frames once placed, create separate animations for stable variants, or build a small lookup system that selects frames by tag/name instead of index where possible. You’re asking the right question because this becomes painful on larger projects 😄