The burner's design record does not hide its hardest problem; it names it. The end-plug — the component that must reach a density ratio of about 16 for closure — is specified as a requirement, not designed, and the record calls it 'the single largest open item' and hands it to the next track.
A plug density ratio of ~16 implies a plug density of 4.16×10²¹ per cubic metre — 347× what the GDT mirror has measured and 26× the best published mirror design. The record names that requirement, states that it does not design the plug, does not cost it, and does not demonstrate it is achievable — and identifies it explicitly as the next track's subject (H53). At the reference ratio of 10 the machine does not close.
Pointing at your own largest weakness is the opposite of salesmanship, and it is exactly what makes the rest of the design credible. A programme that names its hardest gate rather than burying it is a programme whose favorable numbers can be trusted.
| Largest open item | the end-plug density (H53) |
| Requirement | n_p/n_c ~16 (Q_E 1.31) |
| Plug density | 4.16×10²¹ m⁻³ = 347× GDT / 26× best mirror |
| At reference ratio 10 | does NOT close (Q_E 0.63) |
| Status | specified, not demonstrated |