This can be played as a BL and the MC is *not* coded as a woman.
The only reason I don't really use the BL or Yaoi tags is that they're really busy tags with a lot of AI games, and I just am not sure my game would rise to the surface and be noticed on those tags, which isn't true on the otome and amare tags. Since I only get 10 slots for tags, I try to use ones that I think will get my game noticed rather than tags I'm not sure will be helpful. Those tags are just really overwhelmed right now.
It has nothing to do with the actual game genres. But I can always add a BL tag if you think it would help or if it would make you feel more confident the game can be played that.
Though I do not write perfectly, I do absolutely do my best to make sure the writing doesn't imply a specifically preferred MC gender and I take what opportunities I can to differentiate the text based on the player's customisation choices. There is not as much opportunity for it in the demo content because it's very early story development but later in the love interest routes, if I feel there is a scene that might play out differently with a male or masculine character, I will try split the text and write in variations rather than go for a neutral version of events.
This can be small things like using different compliments or visual things like the MC wearing their towel differently if using the masculine base or story related things like the MC leading while waltzing with certain LIs.
Again, it's not always perfect but I do strive for authenticity in storytelling no matter which customisation options one picks!