The selected-building panel counted only outputBuffer.items, so items that had moved onto the output virtual belt (REQ-MAT-OUTPUT-EMERGE) disappeared from the Output line while animating. Count buffered + emerging, and drive the fallback branch off that combined count so a building whose output is entirely mid-emergence still shows its Output line. Input display unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01DZR44tA8sn4dPqDzAVXyps