Many thanks all for your replies 👍
Having never experienced anything like this on any other vehicle that I've owned over the years, I'm just rather surprised that a barely visible stone chip should lead to paint blistering of this sort on such a modern, prestigious car that is presumably manufactured and finished to combat such issues. If it were a common occurrence, I'd have expected to have seen more road users exhibiting patches of blistered paint on their front ends before now.
Thanks again for your replies - most appreciated! I'll update the thread once all is resolved.
(The colour is Cadoxton Slate btw)