It is wrong to assume but presumably re programming the MEMS3 and thereby affecting the interaction with ring around the ignition switch has no effect on the “burglar alarm features”?
Yes, cars with MEMS 3 have this feature.This information is very interesting. Thank you.
Is the exciter ring also present and operating in later cars (with MEMS3).
In answer to the question regarding "can I start the engine with key alone?" , the answer is at this point in time I don't know. I'm fairly certain that the answer is "No" because when I bought the car it only had one functioning fob and key. In other words I had a spare key (and possibly a fob but that fob either needed a battery or re synchronising). The key itself would enter the petrol cap and possibly the door or ignition but not both and not the boot. After a bit of grinding and use of a file I removed some more metal and it would enter all locks and operate each one (but as stated without the fob no engine start as far as I can recall and there may even have been an alarm if tried (but it is a while back now).
I suspect the answer is no but it is worth asking.
Can Pscan establish if the engine map installed in the ECU for a MGTF 135 has ever been upgraded?
I doubt it will tell me what the map is but it might interrogate that ECU to see if it has been changed since the car was produced.