Megan is now running with the oem ECU as if it was a standalone and without the BCM & IDPM.
The electrical issues that prevented to be tuned last weekend is still unknown.
Yesterday I decided to give myself a Challenge to make a new wiring setup that would isolate the ECU from the rest of the car.
There is still some work to be done on the wiring job such as adding some fuses, relays and a switch/gauge panel.
The main Challenge has been completed !!!