"Having your DC be registered and seen might not make any difference to them, because you are not abusive parents." I'm afraid the "nothing to hide, nothing to fear" mantra is very naive. There are many ways in which inspections can do harm. Here's an example. Three examples in one, actually: a nearly identical story has been played out with three separate children just among my own acquaintance!
Child with high functioning autism finds school overwhelming and becomes very distressed. Desperate parent removes child from school to home educate. Child soon shows clear signs of finding life more manageable. Self-styled home ed inspector from the LA invites himself for a series of home visits, implying they are compulsory. Not knowing they have a choice, family agree. Child is very stressed at having a stranger in what he thought was his safe space, and fears that he may be sent back to school where he was so unhappy. He behaves accordingly. Perhaps he hides or says rude things. Or, when asked, "Wouldn't you rather go back to school?" maybe he gives the answer he thinks the LA chap wants to hear. The visitor asks to see the child's "work" but there isn't any because the child loathes writing and usually learns in other ways which don't resemble school.
LA report says that child's social skills are suffering through being home educated ("he hid under the table when I came!") and that they'd like to see some written work. Parent tries desperately to force child to write, in order to get the LA off their back so they can carry on home educating. This backfires, and the parent-child relationship becomes strained. In due course, LA starts to imply that legal action against the family is imminent. This is probably bluff, but the family don't know that. The parent (and sometimes the child if he's old enough to know) live in fear of prosecution. They cave in and send child back to school.
...where, predictably, things go from bad to worse over the following months or years until child has a complete breakdown (self harm and/or suicide attempt) and is withdrawn from school again. This time around, as luck would have it, the parent discovers that the LA had been misleading them and that they can decline home visits. The freedom from this intrusion makes all the difference. Now they can get on with giving the child what they know he needs, and he can start to make a proper recovery.
I know other children who've been harmed by LA home visits. Most have suffered far less than the three I mentioned above. But it's apparent to me that bringing external assessors in WILL cause harm to a proportion of children. I am sufficiently worried about this to keep them at arms' length, at least where it concerns the more vulnerable of my two children. This is a risk I am not prepared to take.