Yes, Delaney, yours is a very American attitude. I meet it in the books I review, often historical romances or thrillers, published by American publishers. When I point out that the research is sloppy and accuracy has been sacrificed for the story I am told this is a 'good thing'!
Getting it right is to do with honesty and writer's integrity. A note to readers saying what was done and why is fine. But sneaking stuff past and thinking readers won't find out is, in the long run, a disaster for sales. Historical novel readers like history and they don't like being conned.
No offense taken, but it's "Deleyan" not "Delaney".
Yes, I'm an American writing for the American market. American readers are out for the entertainment value in fiction, not a history lesson. If you can get the history close to accurate and still provide them with good entertainment value, all the better. Personally, the challenge of Historical Fiction for me is to weave the fiction into the history and keep it both accurate and entertaining--just because the market WILL allow blatant changes to suit the story doesn't mean I have to be weak and always lean on the crutch.
Frankly, it's not a disaster to sales to be less-than-historically correct, not in the States. At least one NYT best-selling Historical Fiction author has some of the
worst historical accuracy I've ever seen--totally getting the very culture horribly wrong--but I think it's what actually has helped the sales of those books because it gives them the culture the average readership expects, not what's accurate. And, yes, this galls me to no end since even the idiotic History Channel gets this culture right.
That being said, the question had more to do with process--do I use beta readers to vet historical accuracy? No, I don't. I do the research before and during the writing, and vet accuracy in the first revision. Beta readers don't see a book until it's through all my revisions and is as good as I can make it. The people I choose for betas are normal readers, which is the only kind of expertise I desire at that stage of the process.
It could be we're just discussing semantics, that you might use "beta reader" to me anyone who reads the book other than yourself, whereas I'm using it for a reader at a particular stage in the process. If that's the case, we're in agreement that it should be done.