My concern would not be having the cost of the boost being reinstated, it's surely just a matter of switching over to the new car in case of a total loss.
My concern would be that, if you had not reported it to your insurer, they might invalidate your insurance, in the unhappy and hopefully unlikely event of a major claim.
Informing the insurer would prevent any such sneaky weasel words biting you in the rear. However, a possible issue is that the insurance agents do not seem to understand what a Tesla is all about - of course they understand the essentials - but anything not spelled out in their "book", understandably, flummoxes them.
Finally, does the Boost really make that much difference? Or, put another way, is it good value? Of course, if the latter were an essential part of our purchasing criteria, we would not buy much
.... or, am I a cynic......
Now then......SWMBO tells me that, thankfully, I do not qualify for Oscar Wilde's definition of a cynic.........