Panel IDs derived from Grasshopper list indices will inevitably break your schedule. The moment an edge condition gets culled or a facade cluster gets filtered by panel area, index 104 quietly becomes index 89. Generate a persistent spatial tag (like `BAY-04_LVL-02_P-01`) directly from the initial UV grid coordinates and attach it to the element's user text or parameter dictionary before doing any downstream data filtering. Never trust list order to survive a design iteration.