I have not finished every book in the quest quite yet so some of these might change later down the line after I finish it. If you know of representation in one of these books that's incorrect/not complete, please let me know.
A - Z But Not Too Bold by Hache Pueyo: Sapphic, Bi/Pan, Latine MC/Author Camp Damascus by Chuck Tingle: Sapphic Deephaven by Ethan M. Aldridge: Non-Binary, Sapphic Earthlings by Sayaka Murata: Asexual, Asian MC/Author Exquisite Corpse by Poppy Z. Brite: Achillean, Transmasc Author Green Fuse Burning by Tiffany Morris: Sapphic, Indigenous MC/Author Grey Dog by Elliott Gish: Sapphic Into the Drowning Deep by Mira Grant: Sapphic, Bi/Pan, Disabled Characters It Came from the Closet by Joe Vallese: Sapphic, Achillean, Bi/Pan, Transmasc, Transfem, Polyam, Non-Binary, Latine Authors, Black Authors, Asian Authors, Disabled Authors Jawbone by Mónica Ojeda: Sapphic, Latine MC/Author Lone Women by Victor LaValle: Sapphic, Black MC/Author Manhunt by Gretchen Felker-Martin: Transfem, Sapphic, Transmasc, Non-Binary Meddling Kids by Edgar Cantero: Sapphic Model Home by Rivers Solomon: Intersex, Non-Binary, Black MC/Author Monstrilio by Gerardo Sámano Córdova:???, Achillean?, Latine MC/Author Moonflow by Bitter Karella: Transfem, Sapphic Not Good for Maidens by Tori Bovalino: Sapphic, Asexual Our Share of Night by Mariana Enríquez: Polyam, Bi/Pan, Sapphic, Achillean, Latine MC/Author Our Wives Under the Sea by Julia Armfield: Sapphic Pet by Akwaeke Emezi: Transfem, Disability Rep, Black MC/Author She Is a Haunting by Trang Thanh Tran: Sapphic, Asian MC/Author Squad by Maggie Tokuda-Hall: Sapphic, Asian MC/Author The Book Eaters by Sunyi Dean: Sapphic, Asian MC/Author The Cabin at the End of the World by Paul Tremblay: Achillean The Church of the Mountain of Flesh by Kyle Wakefield: Achillean, Transmasc The Devourers by Indra Das: Polyam, Achillean, Bi/Pan, Non-Binary, Intersex, Asian MC/Author The Gilda Stories by Jewelle Gomez: Sapphic, Black MC/Author The Luminous Dead by Caitlin Starling: Sapphic The Route of Ice and Salt by José Luis Zárate: Achillean, Latine Author The Sacrifice by Rin Chupeco: Sapphic, Asian MC/Author The Salt Grows Heavy by Cassandra Khaw: Non-Binary, Asian Author The Scourge Between Stars by Ness Brown: Sapphic, Black MC/Author The Taking of Jake Livingston by Ryan Douglass: Achillean, Black MC/Author The Unworthyby Agustina Bazterrica: Sapphic, Latine MC/Author The Woods All Black by Lee Mandelo: Achillean, Transmasc The Worm and His Kings by Hailey Piper: Sapphic, Transfem Walking Practice by Dolki Min: Non-Binary, Asian Author We Came to Welcome You by Vincent Tirado: Sapphic, Latine & Black MC/Author What Moves the Dead by T. Kingfisher: Non-Binary You Weren't Meant to Be Human by Andrew Joseph White: Transmasc, Achillean, Disabled MC/Author