Thanks, Optimissed: very interesting.
Regarding time needed, I am sure there will be specific standard advice from the OU. Took me a while to get what you meant about the maths - you mean he has done a lot of this already. I am sure the OU will explain to him what he can skip, and work out a schedule for what is left.
Hardware in AI is surely important in several ways. One is specialised computing hardware such as google's TPUs, but also GPUs, which serve a similar purpose for most deep learning specialists (because they can be faster than CPUs for the big matrix calculations. Working with parallel hardware of other types is also useful. He may be interested in robotics, which has a lot more varied hardware requirements than most AI work: interfaces in both directions are important. I would see the role of a hardware specialist as complementary to those working on the software and algorithms.
As an amusing coincidence, long, long ago, after I had deserted academia for microcomputers I got interested enough in electronics to do a few modules in it where I could, and found use for that experience later when building automated experiments in applied physics research. An MSc would have been a choice with more potential, but I wasn't so committed to that area. Mostly, I have stuck to working with software, which is more my metier.
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