They probably won't considering 360 UCAS points is equivalent to AAA, which is higher than your firm. However if you get A*A*C then your firm might reject you and your insurance accept you as you've met their requirements of 360 UCAS points.
I wouldn't advise choosing a uni you don't want to go to as your insurance as you need to be willing to go there if you miss the grades for your firm. An insurance unlikely to accept you if you miss your firm offer is better than no insurance choice, and you have nothing to lose so I'd say insure the 360 points offer.