To me, being insured is a matter of general law - legal liability exposure cover, rather than a subject for the CAA. Or are they trying to turn themselves into another DVLC style jobsworth exercise?
Its a matter of EU law, and the CAA are doing their bit to verify compliance as EASAs UK Police Squad. If they were trying to be the DVLA, they would already know if youre insured or not, but by knowing that would do them out of another justification for existance - the confirmation that you're insured but its still up to you to check its enough to be legal.
In fact, I wouldn't be at all surprised in a few months to hear that the CAA have been ordered by EASA to stop gilding the lily in the way they have.
They already have, but just cant quite bring themselves to do it.
Likewise EASA have been told the same by the EU.
one day they might even start shutting down dodgy maintenance companies.
about time too, ..... perhaps even also crack down on dodgy pilot owners who fiddle around fixing things that arent broken, break them & then pass the buck to the aforementioned MOs.