these are what i too disliked abt the story, so i agree with you on that. its not the best k-bl exploring bdsm but its still one of the good ones in this genre considering im sure we know just how bad the k-bl novel market is in general. idk if you've read the novel which despite having tons worse start than the manhwa actually turned out to be pretty good as the story progressed, with the ml seriously having character development which you don't usually see much in korean bl novels, which is why i liked the story. k-bl novels are pretty much a hit or miss so i truly understand your sentiment; not everyone will like the same story and vice versa.
its been a while since ive read it but i personally think the manhwa could be better considering "the foul" manhwa adaptation is much better than the novel because the ml's character was actually dogshit in the beginning of the story. if you have enough patience and tolerance to make it towards the end, he has good development and they turn out to be a very cute and loving couple.
Okay so
Aporia:
https://www.mangago.zone/read-manga/aporia/
The ML knows his tastes and knows not a lot of people can handle that That's why he takes mesures to insure only people that are into that same stuff are ones going into play with him.
Aftercare is also great
My Partner's Taste and Fetishes
https://www.mangago.zone/read-manga/my_partner_s_tastes_and_fetishes/
This one I really liked, because both parties give mutual consent, and are also enjoying the types of plays they do.
Ang Ang
https://www.mangago.zone/read-manga/ang_ang/
Even tho the ML in this case also has more experince than MC, he isn't in a position of power over him. Sure MC is his bodyguard but it's not like he couldn't find work anywhere else. He is also highly trained and can handle rough play, and would've told the ML if he couldn't handle something. He is also strong enough to handle ML if he goes too far. ML also knows MC is a beginner so often times slows down the play even tho MC is eager for more.
The Boss in the bedroom
https://www.mangago.zone/read-manga/the_boss_in_the_bedroom/
I kinda liked this one at first, but it has a lot of problems of it's own. But at least there is consent (mostly) and both parties are enjoying their plays and sexy times so that's a plus.
Love Inks and Museum Links
https://www.mangago.zone/read-manga/love_inks_and_museum_links/
This one is very recent, but has potential. Consent, explanation, safe word, limits, aftercare.
So that was just a few that I think handled the topic od consent, play, aftercare, safe word and so on, much better than this story.
this is the first story ive seen where bdsm is actually explored properly (with consent and good aftercare) IN THE NOVEL BTW. the ml actually has good character development so i hope we'll see the same here (and he'll be less mean.)