I've seen paranormal regencies--mostly traditionals with paranormal elements, I guess. Most of them were bad, but not all. I can think of several ghost/psychic plots, a vampire plot (by Karen Harbaugh), and a vampire-themed anthology (published pretty recently, I think, and including a novella by Kate Huntingdon).
Outside of trads, Madeleine Robins writes alternate-history hardboiled Regency mysteries--not romances, of course, but they're GREAT (they're published by Forge, too). Then, there's my favorite paranormal Regency of them all, Sorcery and Cecilia, by Patricia Wrede and Caroline Stevermer. It's recently out in a new edition and has a sequel. Patricia Wrede also wrote a 2-book fantasy Regency series on her own (Mairelon the Magician, the first one was called).
Anyway, I know probably none of this is in exactly the same segment of the genre as your book, but clearly at some point, someone has thought that fantasy set in the Regency could sell well. =)
Re: I only read part one...
Outside of trads, Madeleine Robins writes alternate-history hardboiled Regency mysteries--not romances, of course, but they're GREAT (they're published by Forge, too). Then, there's my favorite paranormal Regency of them all, Sorcery and Cecilia, by Patricia Wrede and Caroline Stevermer. It's recently out in a new edition and has a sequel. Patricia Wrede also wrote a 2-book fantasy Regency series on her own (Mairelon the Magician, the first one was called).
Anyway, I know probably none of this is in exactly the same segment of the genre as your book, but clearly at some point, someone has thought that fantasy set in the Regency could sell well. =)