I feel like most insurance companies will only pay the value just like it a regular slingshot. I would guess you could do like I did and purchase an additional policy. I actually have a 15000.00 rider for accessories. The kit would fall under being an accessory.
I only know what our insurance has said to us, he said it was a good thing we did not have a 4 wheel conversion, that they wouldn't insure us since we have Motorcycle insurance (USAA underwritten by Progressive).