It seems like I have two options - I either learn to ignore everything in the Calibre Library as per skb, or I just give up with Calibre as a library management tool.
To be honest I have got by quite happily for many years now just using Calibre to edit the book metadata and DRM etc. and keeping my collection catalogued as I want it.
I am tempted to go back to that to hang onto what little hair I have got left.