Shockingly, I think this is accurate:
Imoen is just not characterized in a way that reads as sexual
I'll even give Lily some credit (that will momentarily be taken away) I think the majority of the BG fanbase would agree with him on this statement. Which is (part of) why the Imoen romance got so much pushback in the first place. Because she isn't a character that should be sexualized. Which is why the alternate Imoen *friendship* mod exists that I notice Lily never talks about. IIRC, there's actually at least two variants out there.
It's why this comes off as yet another Lily contradiction because this:
Imoen is too much of a comfort character, and her personality too genuinely comforting and warm to actually see her in a sexual way. There is literally nothing in the world less sexual than her.
is entirely at odds with installing the mod. You can't say you don't view the character as sexual when you install a mod to romance them when there's alternatives available that provide additional content for your comfort character without the romance.
In addition to a classic Lily contradiction, it also feels like we have Lily not understanding a character. I'll actually cut Lily a tiny bit of slack because I think BG1 Imoen was designed to be a warm, comfort character. Like...she was added last minute as the earliest NPC option because the first two NPCs you run across are untrustworthy and the game is 90's hard, so having no party in the beginning is pretty brutal if you don't know what you're doing. Subsequently, that's why Imoen has no real personality, she's just "cheery friend" in the first game. But nobody really has character in the first game because NPC interactions were basically limited to recruitment. Her personality really comes from the VA being upbeat.
But when BG2 was made and we started entering the world of NPCs being able to talk/more complex game stories, everyone started getting fleshed out. And Imoen is actually a pretty dark character. Like, 95% of her dialogue is related to trauma and torture in BG2 because she's really less of a character and more of a plot device. She wasn't even meant to be a full on party member. To use a BG3 comparison, it's kinda like how Halsin and Minthara have notably less to say than everyone else because they were last minute party member additions due to fan demand. Hell, now that I think about it, I think a decent chunk of the dialogue Imoen delivers isn't even really her and just the dream version you see between chapters to basically motivate you to do plot stuff.
It's not until the expansion where she really like...has a character. And...it's fine, it's not nearly as bleak as it is in base BG2, but it's also not particularly comforting or cheerful, either. She's more...hardened. Not to the point of being completely closed off or anything, Really, if I had to classify it, I'd say she's the example of a trauma character basically going through whatever caused the trauma and coming out the other end as a stronger person. They've lost some of their innocence, but they aren't defined by what happened and have moved on. She's also more confident, I think she's like, one of the few characters that outright states in the expansion that you/your party are some of the most powerful people in the world, especially compared to where you were in the first game. And it's not like, a Kestri level over the top boast, and by that point in the game, when she's casting the highest level magic (or at least very close to it if the dialogue happens to fire off really early) she's not wrong.
But when Lily talks about Imoen, it's pretty clear he doesn't see any of that. He also really latches onto the sibling aspect. Which, if you've never played BG might sound reasonable because you assume a certain thing when you hear sibling characters. But the big thing is, Imoen wasn't ever written to be your sibling and that dynamic was never meant to be explored. It's not like Full Metal Alchemist or something similar, where that relationship is like, the heart and soul of the characters. It's really more of a plot convenience, to the point I think if the decision to keep Imoen alive wasn't made last minute, I suspect they would have dropped it entirely, because in the expansion, when she does become a character...that's basically what they do. Like, they pay lip service to it because they have to, but it really feels like they want you to forget it more often than not.
But Lily likes incest. And while he says this:
I said not too long ago that characterization is extremely important to me, and I meant it.
what he really means to say is the characterization that he makes up is extremely important to him. Lily likes his very specific version of Imoen, which has nothing to do with the actual Imoen. Much like how Lily likes his specific version of WoW that's all about how great his slave owning elf is, not like how the actual WoW story goes. Or how Lily likes his specific version of Star Wars that has nothing to do with actual Star Wars. And, hey, I get it, that's a big part of the appeal of making mods in the first place. It's fan made content. But Lily acts like it's the official version of the character, and ignores the real version in favor for the fanfic version. Or I guess it goes one layer deeper than that, he ignores the real version in favor of his version of the fanfic version.
But really, what it comes down to is the incest of it all. If you kept everything the same but just tweaked it so you weren't siblings and still childhood friends like the original intent for the character, and Lily would have no interest whatsoever in any version of the character, fanfic or official. Which will probably be the TLDR of whatever overly lengthy post I make once his video releases.