extras.benefitRating is null in v1. The rating phrase ("erheblicher Zusatznutzen" / "beträchtlicher" / ...) is stored inside the BAnz/TrG PDF text, not in the HTML detail page. The PDF URLs are surfaced in documents[] so subscribers can click through. v1.1 will parse the PDF text and populate benefitRating automatically.
v1 monitors only the most-recent ~30 Verfahren on the public listing. Historical backfill of older AMNOG Beschlüsse is not yet supported (queued for v1.2 as an opt-in snapshot mode).