The link I provided looked very similar to my own kit, purchased in UK pre-Brexit. I know it was from Poland but postage within Europe (not UK) should be quite quick.
Petrol ECUs don't usually suffer from wet like the diesels but any ECU can fail, which I have experienced on one of my KV6s. However the most common reason for non-starting later models is the fuel filter, some petrol might be reaching the fuel rail but not enough pressure.
I saved this link ages ago, perhaps they can test your own ECU?
https://auto24parts.com/en_GB/p/ECU-...5-A0009-/16976. Yes Poland again, clever people - invented Toaf
Thought of a method of draining some petrol using the car's own pump - disconnect the incoming fuel pipe behind the battery and run a hose to a container, raise the rear seat and identify the pins on the fuel pump, black and white/purple (minus & plus). Apply power to just those pins and the pump will run until disconnected.
Good luck