The thing about Kuro is that if you don't at least acknowledge that sebaciel is real in some respect then the only thing you're getting out of the narrative is a series of events. Because their character development entirely revolves around their relationship with one another.
They don't have strong relationships with other characters, and this is by design. So if you refuse to see the text (not subtext, text) of their relationship, then you're literally just reading a timeline of things occurring with no real human element. And that's tragic, actually.
And the funny thing about text vs subtext for Kuro is that if you're looking for flat textual confirmation of anything in this series, you've fundamentally mistaken the sort of storytelling that Kuro utilizes. Because Kuro is very big on showing vs telling. Much more can be garnered from the characters and the story through their actions rather than their words because most of the characters have compromised credibility. The overarching theme of the story is deception and lies; this is not a story where just because a character says something that it serves as 100% unbiased and factual.
The "subtext" is a part of the storytelling. It's part of the text. It's not something that's accidentally mentioned. If you refuse to read what's a fundamental part of the text, I don't know what to tell you.