You've just answered your own point. Fitters checking things, doesn't mean a failure. They could be monitoring the tests of the units while they are out in service.
If these keep failing at Upton, then it opens even more questions, such as, Why Upton?
While I'd agree with most of that, it's not solely 230's they are covering. They are covering for failed Mark 4's and about 10 Class 231s that are still doing Valleys work.
But it's been discussed time and time again, the 230's are here to stay. There is a lot of work going on in the background, and it appears that things are moving forward to get 230's covering full diagrams, albeit slowly. Nothing is going to change that now, and people could really do with having some patience rather than reposting the same posts every few weeks.