My framework's most useful structural distinction: two ways to matter in a supply chain. Bottleneck participation is supply‑side scarcity—owning capacity demand exceeds, like laser fabs or substrate crystal growth. Control‑point participation is architectural authority—shaping design choices regardless of capacity. The switch‑platform layer is the most explicit control point. The axes complement; deepest positions combine both, most fragile combine neither. Evaluation asks separately: is capacity scarce? Does it shape decisions? One yes is a position, two a franchise.