SGUL allow intercalation. As do Liverpool, Manchester, QUB, Cardiff, Leicester, Exeter, Plymouth (Peninsula is now split into separate med schools). Most of them would let a student intercalate at other med schools, I believe. Places on a AFP or ACF programme are blinded to the med school, so going to any med school in the country does not affect chances of a place. (I have just selected med schools here that do not require a high UCAT, though do not know what your daughter scored).
I am not sure what leads you to say essentially UKCAT, rather than actual A level performance, is being used as a filter for those who might want to keep doors open for research orientated careers? You can get a place on an academic programme from any med school and most allow intercalation and other opportunities to increase points for application. Your DD could have had a place at a top research uni from almost anywhere.
Also, I do not know why you say Academic DC really ought to consider the more academic courses. Surely, they ought to look at where they stand a good chance of an interview and choose the one they like best out of those? Some want early patient contact, PBL, etc, some don't and they should not be pushed into choosing something because they are labelled "academic" or not. A poor UCAT does not deny applicants having both academic and vocational parts to their course, although it may limit choices.
I think it is unfair to call the UCAT a lottery, as there is extensive research into outcomes and refinement of the test to try and produce the outcomes they desire - an applicant who will perform well at med school and beyond. But they, unfortunately, do not have the resources to do the type of assessment needed to make sure all aspects of an application are fully assessed (I go back to my 3 month "structured assessed work placement.....), so they go with the best of what is available. Which at the minute is the UCAT.
I have not read all past threads on MN, but I think I have shown that I am not influenced by people shouting loudest or insisting they know best, with no evidence to back that up and I persist in my belief that the UCAT is just one part of the system and we need to encourage and support our children to do whatever they are able to do to increase their chances of a place and then help them research the places that suit the strengths they have. I tell a lot of people that sometimes they need to decide if medicine or the university is more important, as there is nothing different in terms of opportunities in the NHS for graduates of Oxbridge, UCL, Imperial, Plymouth, ARU or Aston (or any other med school).
I am also a parent of a child with learning difficulties, so have shared many of your frustrations, but our extra special DCs do not mean the system is wrong, just that, sadly, it caters better for the many than the few (as is true for so many areas of life!)