I couldn't find this on the forum, but does anyone know how intercompatible MEMS units are. Would any MEMS unit with the same version (as in MEMs 1.6, 1.9, 2.0, etc.) be intercompatible? Is there intercompatibility as long as the cars they came from are similar? Or is getting the exact part number an absolute requirement?

I ask because I've been struggling to get an exact match for my ECU (MKC103580) and have been offered ECUs from nearly identical cars.