Will writing occupies an unusual legal position: in England and Wales it's an unregulated activity – you don't need to be a solicitor – but the claims profile is anything but casual.
Buy limits against estates, not fees; guard your retroactive date like the asset it is; and plan run-off into your retirement maths – in a profession where claims arrive posthumously, cover that stops when you do is barely cover at all. If you add trusts, LPAs or estate administration, tell your insurer; each changes the rating.