Personally I'd rather deal with the Chief Engineers of BMAA and PFA than much of CAA, but maybe that's just me. I think both are rather more helpful and has on-tap expertise at-least as great as most of CAA.
CAA decided a few years ago that it would only accept reports from an "approved company", that is approved within the terms of FAR-21, JAR-21 or BCAR Section A. They will accept reports from overseas companies approved by their own national authority - but CAA won't accept reports from anybody in the UK who isn't an approved company, nor will they give approval to anybody outside the UK.
This messed up a number of small consultancies and killed the attempts to certify the Masquito helicopter dead when it was brought in about 2 years ago. It's totally separate to the use of JAR-VLR or BCAR-VLH which don't mention company approval issues.
And trust me, if you are an approved company you'll know about it from the certificate on the wall and annual £3-5k bill for the privilege. You may have been granted "grandfather rights" when you weren't looking, but I wouldn't bank on it.
G