Rover MEMS ECU question

[QCcanuck]

All,
I'm completely new to the whole rover ECU mems thing and wanted to get a basic question cleared up.

I'm helping sort out a car with MKC104080 acting up and managed to source an MKC10115E on the cheap. The car is a 1996 Morgan plus 4 with the Rover T16 (natrurally aspirated) engine. I know of another plus4 with the T16 engine that is running the MKC10115E (I don't have access to that car but i know that model is working fine for it).

The question i have is, considering the ECU is not being used on the rover cars , is the reason both MKC models seem to work on the same engine that the use case only needs the basic functions of the mems?
If so, can I expect that the new ecu would be a straight swap (it's brand new in box so i'm really looking to see if i have to worry about coding/immo off although i believe those models are immo off already ... i think/hope)

Your help and guidance is , as always, much appreciated

-M