I believe the only thing that has to be coded out is the bulb check, which will cause LCI lights on non-LCI cars to flicker when the car turns on. This is caused by the system checking the draw to see if a normal halogen bulb is out. Because LED's are totally different and draw much less power to operate, it causes the lights to flicker during the bulb check.
I don't think it throws any error codes, just the bulb check flicker. This can be coded out pretty easily.
Anyone feel free to correct me if i'm wrong