If I have read both BA policies correctly, (one gives a max of £4k - the other £10k cover for miles bookings) then it is very important to note that to benefit from the BA Miles insurance element you have to cancel within 24 hours of departure. Cancelling before then means that you can cancel within the terms of the Miles T&Cs which can leave you worst off. It also doesn't specify clearly how they will reimburse you ie is it the cost of an F ticket if you cancel an F ticket within 24 hours of departure?

Perhaps someone else can give their views of the policy wording?