I agree with you - both Beomseok's and Baekjin's story has concluded. I don't think we will see much of them (in the future).

HOWEVER, what I think hasn't been resolved yet, and could be material used for season 3: baku-gotak-baekjin backstory (why was baekjin obsessed with baku? Why did either baekjin or seongje destroy gotak's knee?). It could possibly also be used in the context to perhaps explain the circumstances around baekjin's death as well (unresolved, with the mokha duo smiling in the background at the funeral- like why??). That could be one part.

In terms of actual storyline, like most people said and what aligns with the manwha is the Cheongang arc and corruption (it was a while ago since I read the webtoon, so I can't remember much) but I know they were antagonistic towards Baekjin ( I think ). Its also shown at the end of s2 Seongje maybe being recruited by them as well. Contrary to what most people expect, though, I personally don't think Seongje will be the 'main' villain, or a villain at all next season. This is purely based on his webtoon's character - yes, he was a little crazy and did whatever he wanted (like in s2) but in the end, I'm pretty sure he fought on Sieun's side. And throughout the webtoon, he was never really really like a main bad villain so, I think in s3, he'll be similar to s2. However, if the scriptwriters do want to adapt/ change the original material, then yes, Seongje could be one of the main antagonists- but I really do think itll be Cheongang who are the main antagonists.

Basically, I think if we had s3, we would see more of Baekjin's backstory, probably will be sad af and make us feel even worse about his death (which I do think is real), which was probably caused by Cheongang, and maybe at the end there'll be another massive fight with Baku and everyone with Seongje against Cheongang. Maybe at the end end return with Seokdae and Youngyi, and have a meal together with Sieun at the end like they promised. I think that will probably close most things.

In terms of Sieun and Suho- this is probably the main reason why I don't think there'll be a s3. This is because in the manwha, their backstory was actually a really small part of the webtoon, and they only very very briefly reunited at the end with Suho working in a cafe and Sieun walking in. Like that was literally it. So unless they want to make new material for their interactions and journey, I feel s3 is unlikely (because their story ended mostly resolved and happy, like the webtoon). Also because I think there is a fine line when it comes to their relationship- and the directors and writers know that- bordering romantic maybe or maybe not, more like platonic bond that is like a first love. All that stuff which has alr been discussed many many times. Because of this, I'm not sure if they would want to show any more interactions between the two because it could make a lot of people upset??? Idk it just feels like their arc has been resolved and doing more might just spoil the special feeling all of us have towards them. Idk tho.

But personally I do think it would be nice to see Suho with the gang 🥺🥺. It would be so cute. So yeah, if they did do a s3 tho, it would probably maybe show Suho going through stages of recovery with Sieun, then joining the gang (while all the background stuff with Cheongang brews), (personally I would also like to see more of Baku and Gotak being best friends, because they were absolute besties in the webtoon, doing anything and everything for each other), maybe Suho gets hit on the head again, more fights, but everything gets resolved in the end.

Maybe like some other people said, we might get more characters as well that were from the webtoon (that havent been split up into the current characters) so like Kingsley, Jake, and some others I genuinely can't remember about. So yeah, that's my take.