A rather late answer, I’m afraid.
A few years ago I found Hiscox rather expensive for house insurance so I switched. At the moment I use John Lewis. They cover for extended periods of time away from home and seem reasonable concerning terms and conditions. They don’t specify about the type of lock (eg Gold Standard). When away from home the bike must be locked to something solid but they seem happy for my “fleet” to be just locked to one another in a locked summerhouse.