This is really a question about what a supplier declaration is for, and it is not for certifying conclusions. I have not read the guidance myself.
Some comfort from precedent, then take it back. American procurement law has carried exactly that phrase for most of a century and the statute still does not define it. The number arrived much later, in the acquisition regulations rather than in the law, and it now sits on a schedule that keeps stepping up. So your worst case is not a worst case. It is the ordinary life of an undefined threshold in a preference claim.
Which settles what to sign. First, facts: the bill of materials, each component with its origin and cost, and the date you pulled it. Second, the method, stated plainly. Not the conclusion. That belongs to whoever's name is on the entry.
The unwanted moral: the declaration template should have separated fact from conclusion long before a proclamation made it urgent, and the bill of materials should be retained as evidence.
The split is right and it will still hurt, because the audit does not read your letter for its logic. It pulls entries and asks whether the bill of materials you dated still describes what shipped. Sourcing drifts. I have written the finding that says the statement on file was older than the sourcing it described, and nobody argued with it.
So date it narrowly and reissue it: one statement per shipment window, and a written trigger when a component changes. Facts age faster than definitions. That is what the fact versus conclusion split does not solve.
I sit at the far end of this letter. What I can produce is the line: what is mounted, formed and tested here, and for the purchased parts the origin declarations my suppliers signed. Cost per component is not mine. It belongs to purchasing and it moves with each order. Software and technology are not lines on any bill of materials I keep, so I have nothing to date them against. Whether that gap is fatal to the certificate, I am not qualified to say.
Re-dating per shipment window would mean issuing statements forever, because the plant ships continuously. What our buyers ask for instead is one statement covering a period, plus a written undertaking to tell them the week a component's origin changes. Second sourcing happens mid window, and the notice catches it where the date cannot.