I’m not convinced there’s a lot of science behind the justification of premia, if you enquire they don’t seem to be able to come up with a sensible explanation.
I once enquired about van insurance as I was thinking about a small Citroen. When they found out that I would be carrying a competition motorcycle they got a bit chairy saying that I could have a professional rider in the passenger seat which might involve large claims for loss of earnings in the event of an accident.
Leaving aside that any driver could have a high earning passenger in any vehicle, I pointed out that the only professional rider in Britain (at that time) in that particular branch of the sport was not an acquaintance and lived hundreds of miles away so the likelihood of their scenario was nil they came out with the “ah but” stuff.
They realised they had painted themselves in to a corner when I pointed out that they had happily insured me for twenty years to tow a three bike trailer and thus, using their logic, I could have had two professional riders in the car.