After looking at the VCA website it seems that issues with in-service vehicles is not within their sphere of operations, and their "contact us" process more-or-less eliminates the possibility of making a general enquiry. They do refer this sort of question out to DVSA and IVS to both of which I have already written, DVSA on 06/11/25 and IVS on 07/11/25. Both of these have quoted response times that mean it is unrealistic to expect a reply for some while yet.
If anyone else felt so inclined to raise the issue with them the email addresses are
enquiries@DVSA.gov.uk and
IVS.ENQUIRIES@dft.gov.uk respectively.
It is also possible to report a safety defect (which I would argue that this is) directly from the page
What to do if your vehicle, vehicle part or accessory is recalled, has a registered fault and how to report serious safety defect you find
www.gov.uk