I think we may need to define mistoricals better like a category one mistorical and category two mistorcalsc...etc
I'm thinking Category One Mistorical would be like Tessa Dare's Avons and Theresa Romain books. Where the writing immediately sounds contemporary and the plot is too outrageous to fit the time period. There is references to too many modern sayings and the dialogue does not sound right.
While Category Two would be like Grace Burrowes, Jennifer McQuiston, Sherry Thomas possible Shana Galen where while it may not have happen in that time period it still somehow can be overlooked because the dialogue and the writing fit the time period.
Category three would middle of the Road like Karen Hawkins, Sabrina Jefferies, Amanda Quick and Julia Quinn...etc.
Mistoricals is such general term I think this may help us know whether we may like the book or not.