There are generally 2 types of tunables in the ECU, maps and settings. All of the maps are super easy to identify, they start midway through the file and are one after another. At the very least there will be IAP and TPS fuel maps, and ignition timing map, maybe injector balance map. The settings are the things like speed limiters, disabling fuel cut off on decel, etc, these are harder to find as they require the ability the disassemble the bin and follow assembly code around to reverse engineer. This is the part that I am still learning to do myself. Creating a definition file that exposes all the maps will only take a few hours. I have no idea how long it will take me to learn how to create the settings patches. The flashing process itself only takes 40 minutes.I'm interested if you can get things sorted out. As far as you know what can be altered? IAP and TPS maps? What about ignition timing and rev limiter?
And more importantly how long would it take or would you create a new map and install it on the ECU? Let me know how things work out and I may get my hands on a used ecu and send it to you. I found their not that expensive.