As I understood it, even in the UK there is the concept of a 'reasonable man' as in, the contract should perform as a 'reasonable man' would expect. If it does not, that is enough to get such terms discarded. So, you cannot just obfuscate the contract with impenetrable legalese that excludes reasonable things and expect to get away with that. Which is not to say that (insurance) companies will not try.

my source for this was an ex career insurance man (retired out)