C-D21-CAMPAIGN

Full signature-narrowed campaign feasibility OPEN: per-query narrowing is validated, but seeding the first prime's signature set still reduces to D20 enumeration unless a meet-in-the-middle seed generator supplies it; no campaign verdict is claimed until that is built and its cost measured

In plain language

The per-prime check is fast now; whether the whole 294-prime campaign is affordable is the next open measurement.

Exact statement

Full signature-narrowed campaign feasibility OPEN: per-query narrowing is validated, but seeding the first prime's signature set still reduces to D20 enumeration unless a meet-in-the-middle seed generator supplies it; no campaign verdict is claimed until that is built and its cost measured