lets give you an example to work on, if I connect this to a mercedes benz E320 - with M112 engine - how would you satisfy the ECU requirements of correct MAF signal, correct MAP signal, correct mixture read to keep the trims at the 5% value? This car also uses the MAP signal to determine shift aggression and engine load and appropriately downshifts or upshifts to keep the car at best acceleration and best fuel economy.
It uses a total of 4 oxygen sensors - 2 pre cat (1 cat per bank) and 2 post cat - then 2 cats are placed to clean up whatever was left. Very similar to a 2GR-FE toyota or Nissan VQ35.
In any case all above engines use MAF and MAP sensors to detect air flow and load. Does your device bring back LTFT of a whacked up engine? Lets say the same mercedes with worn out MAF, worn out O2 sensors running like crap and guzzling fuel. Im very very sure your EC1 unit will have an impossible task to do - that ECU detects acceleration of the flywheel per "ignition event". 1 misfire is all it takes to shut down that specific cylinder and log a fault code.
I see that your system does not handle ignition timing - yet you are all about playing around with sensor inputs. It will NOT adjust timing thinking its ideal ratio while you are trying to make it see rich mixture while you lean it out. In carburettor terms - you are trimming out fuel without recurving the distributor centrifugal advance - we all know what happens if you dont.
Can you please post a screenshot of an ECU readout with this connected.