you truly analyzed it all so well!! I never thought about how the door is also a metaphor for how everything that happens to Jingi is sealed away.
And the snow scene was already so beautiful, but you added so much depth to it!
The author is so good at putting meaning and foreshadowing behind so many parts of the story. They even posted character playlists, and the songs tell so much about the characters! (eg: on Heonjae’s playlist was Road Kill by Lalleshawri and Jingi’s I’ll Stick Around by the Foo Fighters)

Finally caught up to the latest chapter, and just wanted to discuss how I appreciate the characterization and symbolism.
The confession chapter with the veins extending from Heonjae's beating heart wrapping around Myeong-il, which is a perfect way to not only symbolize how Heonjae's feelings are suffocating and tying Myeong-il down, but also illustrates the nature of Heonjae's love: his "love" is more possessive and an infatuation, where he doesn't want Myeong-il to stay, he wants to force him there.
The piling snow on Jingi when he realizes his mother is dead, illustrating the weight of the loss of his mother, the coldness and emptiness he feels, not only for the loss of his mother, but also how it reshapes his vendetta. If the person whose burden he is carrying and is also part of the reason why he is trying to get revenge is gone, then what does that mean now? In addition, it's also a reflection of how Jingi carries his burdens and his trauma; rather than allow himself to feel the weakness and the vulnerability that comes with being human and a victim, he would prefer to disassociate and become hollow, as in his eyes, being pitiful and being weak just makes you a prey to the strong. Jingi doesn't want to be the prey. He wants to be the predator. He HAS to be the predator.
Lastly, the repeated visual of the door after Jingi went with his uncle is absolutely horrifying. The unseen horrors of child abuse and the uncomfortable repetitions of that exact door until the chapter ends just speaks a thousand words. The length of Jingi's suffering, a closed door that never opens where no one can save him. There is no sound. There is no hint of what's going on inside, but we all know what's happening. We know, but the world doesn't. The uncle has created a power vacuum, where no matter what horrors he commits, it's all sealed and closed off behind doors. Where no sounds leaks. No information leaks. And the world continues, not knowing that there is a predator being protected by the very people they seek for justice.
As much as everyone in this story are terrible people, the author does good to humanize them without excusing them. Never once does the author justify their actions, but they will tell you how they became that way. Part of the horrors they lived to give you a human, and not a character.
This all may sound stupid and poorly written, but I had to get my thoughts out lol