Hi Mark,
not an expert and not sure how much help can I be of,
i went through this a few months back and found a useful picture detailing all types of mmi, from what i can see, you have the same as mine 3g low,(is not that bad) colours on the screen compared to my previous Audi. 😉
i tried to update my software and watched a few videos, followed the steps, downloaded the upgrade on a memory card and could not start it(needs pressing a few buttons at same time etc)I remember so I gave up at some point as my maps are a bit outdated but they work(compared to yours) also not really trusting the car gps when we have phones with more accuracy and different routes etc,
once I am done with my lights project, I will give it a go and try installing the software again and if I can make it work i send you the how to and all links
sorry for not having a solution asap.