Recommendations

Both FLs are seemingly killed but have their faces/identities swapped with another woman who has a brother.

Both FLs are wronged, seemingly killed in a fire, get their faces swapped with another woman, and become part of that woman's family, assuming her identity. They then continue their quest for justice under that identity with the help of the ML who is a military man.

Both are historical dramas that have a powerful queen pushing her son(s) to the throne, scheming by people in the people, and an heir to the throne who grew up outside the palace unaware of his identity as a child.

Both are historical dramas in which the ML is a prince who ends up on the run outside the palace, and helped by the FL who is unaware of his identity. Both MLs have a half brother who palace people are scheming to put on the throne in his place.

Both FLs are the daughter of a man wrongfully accused and executed, and both assume a false identity and become swept up into some pretense regarding gender (marriage to a girl pretending to be a boy vs. attending school disguised as a boy).

They're sort of a gender flipped version of each other - one of the leads (ML vs. FL) has a strange curse/illness that makes them react to something and the other lead fixes them by letting them drink their blood.

Both are historical mini dramas with the same leads as the main couple, and in both the ML is a prince and the FL has a secret.

It´s spicy. 
Kind of the same vibe, like a cold top and a cute bottom.
Taikan Yoho is a story where the characters know each other longer, but they don´t know each other at the same time, if you know what I mean. their only connection? living together and having sex.

Both Udagawachou de Matteteyo (Yashiro) and About Youth (Ray) feature characters cross-dressing. Both characters are tough but vulnerable - their motives for dressing up appear to come from different places.

It’s wrote by same author and shared universe with blank the series. Some of Pluto novel appear in blank the series.

Similar:
Must escape big bad enemy
Action packed
Identity plays a role in the story
Dark

Different:
Mainly about male lead
More romance oriented

Deep Night seems to be a bl version of Mama Gogo: hunks dancing in a host club. There is some romance and danger involved.

The synopsis is similar. Both ml and fml in both dramas grow up together on a small island. Due to some issues, they go separate ways and dont meet for many years. They coincidently meet again after many years when one is having a hard time. They look after each other, become the sun, and overcome the issues.

Bundai Dok Ruk is similar to Lom Son Rak :
-Twin male lead
-2 female leads
-Serious twin vs sassy twin

All though both dramas have different plots. But they share some similar ideas.
- FL leads have similar personality.
- ML is intelligent and loving.
- Both leads pretend to be a couple and continue their investigation.
- both leads slowly fall in love.
- Both dramas have gun fighting and action scenes.