Thanks for the explanation, Kevin. I think I have a slightly better understanding of how spellchecking works now.
There is always going to be this issue with US vs UK - as Shaw is reputed to have said "England and America are two countries separated by a common language".
I know you said not to bother but I have opened my UK word list in MS Word and I am using that to spellcheck it. Using that it has returned less than 20% of them as misspelled, which I am checking against a couple of on-line dictionaries.
It would be great to be able to use the OED as a reference, but unfortunately my budget does not run to that.
I would never expect a dictionary to include people's names. I put them in a separate user Names dictionary as I come across them.