Anybody researching ancestry needs Middlesex., so I see no problem with that. Personally I'd like to forget all the modern names, which keep changing anyway. I don't find many genealogical references to South Yorkshire, which is why I placed Brampton Bierlow in the West Riding.
One problem, of which I am guilty, is creating e.g. Hounslow, Middlesex and then placing it in Middlesex. It appears to be duplication, but it does mean that the category is clear on the profile. It's particularly relevant when two identical place names occur in different counties.
Many London references are to be found in the London Metropolitan Archive, but I think that is a different type of category.