This is not an academic work but I'm including it anyway because it could be a useful resource. It includes quotes from a number of authors working at the time, as well as editors (including Vivian Stephens) and describes how romance was changing in the early 1980s.
There are short biographies of a number of authors but I've not tagged all of them, just some of the ones who're given a bit more attention/who gave quotes. For example, there are some pages about how Jude Deveraux dressed dolls to understand clothing/fashion for her novels (141-144), Bertrice Small claims to be "partially responsible for soothing things down" (127) with regards to rape in "bodice-rippers" (there is more about rape and sex elsewhere, including 139-140) and Roberta Gellis commenting on marriage in the Middle Ages (145-46).
There are sections on different publishers, including Candlelight Ecstasy, Silhouette, Tapestry Romance, Mills & Boon, Harlequin. As evidence of how Gallen went "a step or two further" than other romance publishers, it's mentioned that "In By Invitation Only by Monica Barrie [...] two minor characters become involved in a homosexual affair" (182).
The book includes a lot of photographs of covers, and there's some discussion of cover art: e.g. re Silhouette specifically, on page 166, and then more generally, including entries on specific illustrators, on pages 276-302.