This may or may not be helpful to you (or others reading), but here goes.
My insurance company considers anything on the original purchase order to be covered. So if your car is totaled, the insurance company should consider the value of anything, software included, on the original bill of sale.
If you purchased after the fact, like I did, I got a rider to cover aftermarket equipment. The policy included $5000 in aftermarket equipment, and they added a rider to add I think $8000 in additional aftermarket coverage. So, if my car is totaled, I have appropriate coverage for the entire FSD purchase price.
I do not know how they 'value' this in a payout in the event of a total.