THIS IT JUST ENDED ITS SO GOOD however please read it on webtoon!! all the episodes are free for now, u can definitely finish it before the daily pass starts https://www.mangago.zone/read-manga/concubine_scandal/
https://www.mangago.zone/read-manga/kusuriya_no_hitorigoto/ (st)
https://www.mangago.zone/read-manga/get_the_heroine_s_script/ (bl)
https://www.mangago.zone/read-manga/hime_muko/ (bl)
https://www.mangago.zone/read-manga/her_shimcheong/ (gl)
https://www.mangago.zone/read-manga/chouka_kou/ (st)
https://www.mangago.zone/read-manga/yuukoku_no_moriarty/ (bl subtext )
https://www.mangago.zone/read-manga/sayonara_rose_garden/ (gl)
https://www.mangago.zone/read-manga/emperor_and_the_female_knight/
if you're into extreme extreme slow burn and realistic romance
it can be bl/gl/straight as LONG as its non toxic and i dont want any of the fl/ml to be the super soft uwu "your r-r-royal highness-!" type