Any idea on how this could have happen with such low miles to prevent for the future ?
My 2 Jaguars had similar timing chain noises as they aged near 6 years and 50k miles..
Both Jags were supercharged vs the turbo charged engine in your Maser.
The plastic Jaguar timing chain guides would deteriorate to failure just as the Factory Warranty expired.
My sense is that the more exclusive (low production volume) the brand, this yields less TQM (Total Quality Management) on part failure redesign as the lower sales revenue, than say at Toyota, just can't support the added re-engineering costs.
That's why I initially questioned the oil quality, source and regularity as it impacts how well the timing components stay lubricated as the oil and the engine ages.
The timing grumbles would certainly yield the misfire/camshaft OBD Codes you noted. P3xx
The other codes point to poor battery performance and that's why I asked on the battery age and how the dealer refused further diagnosis (Dx) last month for you.
To be clear, this is not a firm diagnosis as a famous quote reads: "Diagnosing engine noises over the web, it like getting a haircut through the phone."
I totally feel your pain mate..
You've only put 30k miles on her and yet here we are..