If you're looking around for better insurance, you might want to check out Antiques & Collectibles Insurance Group
https://aciginsurance.com/
I've been using them for nearly a decade and check their prices every year against CIS and they are always lower. You do need to individually itemize and send them an image for any single item >$5K which is initially a bit of a hassle and for some collectors here probably too much work for the savings. I think CIS only makes you do this for items >$25K.
I have not filed any claims with them, though, so can't comment on the claims process. They are associated with an antiques association so would assume they are pretty decent to deal with for claims but don't have any proof of that.
jeff