Babylon’s direct liquidation bypasses Aave Hub’s WBTC lending and custody, not the payment itself. Liquidation still involves three payments: the borrower’s debt is repaid in the debt asset they selected; the app charges a liquidation fee of 0.5% of the liquidator’s profit, and even the borrower’s fair compensation is denominated in WBTC and fronted by the caller. Setting the app fee to zero requires a timelock; even if both the fee and compensation are zero, WBTC-denominated debt must still be paid in WBTC. At the time of evaluation, the contract had not yet been deployed on Ethereum mainnet, and the public address pointed to Sepolia.