Cheers for the support! Nope, ECU reset cleared the existing codes and no nasty new surprises so far (prob 300 km since).
Only slight worry I have is Rosco's awesome ECU reset guide doesn't quite ring true on mine. The 'no code' sequence flashes way before I've been driving for a minute, and will flash equal 'on-off' even while stationary. The other difference is that the CEL is on as soon as the ignition comes on when the connectors are plugged together. The accelerator full down, then half up doesn't seem to matter - though I do that anyway.
Code on the outside of the Unisia Jecs Y7 (green) ECU is 22611 AE802 A18-000 D3L 0418.