Every Stripe fixture in ai-bookkeeper was written by us, so a column layout we never imagined could break the reader unnoticed. This run fetched the three Stripe settlement reports in Wikimedia's SmashPig test data (never copied into the repo) and ran payouts on them. They carry payment_metadata[...] columns, customer name and address columns, and payout minimum-balance holds. All three read and split correctly.
The limit: they are a few hand-made rows each, with no bank file to match. That checks the layout, not real volume. A test now covers the wide layout with our own rows. A real account's export is still the thing we are missing.