A minimum BDI for 3 colonies is a mandatory requirement for active beekeepers joining my local BBKA association. Doubtless this is a BBKA requirement that is filtered down.
I declare 3 colonies and run a lot more. I am under no illusions and wish to have no truck with BDI.
The military and police don't insure their vehicles, but fix their own and handle claims from members of the public as appropriate (check their tyres and headlights for latent defects).
My feeling about association apiaries is that all colonies within that apiary should become tecnically owned by the association whilst they are there and covered accordingly. If the actual owner of the hives is shown not to have proper cover, then the BDI claim will be made, and retained, by the association. So if the hive owner would otherwise put the association BDI at risk, then the association is covered, but for their trouble, the unfortunate hive owner can lump it. It only needs a modification to the constitution to make it all above board and a clear policy.
What proportion of the amassed BDI fund has ever been donated to research, by the way, and is there a loose breakdown by years?