I understand your concerns about AI. In fact, I often feel that AI's writing is very deliberate and not natural enough.
However, my idea is not to completely rely on AI to generate new dialogues, but to fine-tune existing excellent dialogues. For example, while preserving the original meaning, use AI to automatically identify and replace some obviously masculine language and inner monologues, and polish them into expressions more in line with FMC. This can both change the awkward feeling of a woman's face with a man's heart and effectively reduce the author's workload.
Of course, I don't actually know if AI can do this. This is just an immature idea of mine.
I don't think it's appropriate to compare erotic games to large RPGs like Mass Effect, because the genres and their core focuses are fundamentally different.
Large RPGs focus on world-building, combat modes, and gameplay. The gender differences in dialogue have a relatively small impact on the overall experience. More importantly, the protagonists of these games are part of a larger narrative, and their actions and dialogue serve to advance the plot. Erotic games are completely different. They focus on creating a specific emotional atmosphere through delicate dialogue, including romance, seduction, and eroticism. Dialogue itself is crucial to the core experience. The story revolves around the protagonist, requiring a more nuanced portrayal of gender.
Therefore, I'm not asking for completely different personalities, but I believe that in erotic games, it is crucial for the dialogue and inner monologues to be more aligned with gender.
Even if the game is otherwise well-made, if the dialogue is still masculine when choosing a female protagonist, it creates a jarring disconnect and undermines the immersion.