Ok so I’ve indeed had to walk away from the manual. There’s no fix in sight and it is now with engineering at JLR as the dealer has tried everything in conjunction with senior JLR technicians and nothing is working - it keeps blowing cameras day after day: I think this car is getting auctioned! Such a shame because I liked the idea of owning a manual prototype.
However, the alternative they’ve offered me on a good deal is a V6s instead of a V6, plus 20inch turbines, pano and meridian as well as performance seats in Ivory and the same exterior colour. Better service history, 20k miles and a year newer so have gone for that, although an auto.
Massive thanks to simpleR for help on the background etc.