Well thats certainly something, obviously im not the target demographic for yaoi so I dont really read any but I knew a lil bit about the omegaverse through Gigguk streams. I thought the omegaverse had to do more with the hierarchy of peoples relationships and their dynamics rather than a biological change, where males can impregnate one another. But regarding that, where exactly does the baby come out of? Their front or behind? Or do they js come with the full male and female package like futas?
well for the most part you don't see the delivery part of the pregnancies in mangas (with some disturbing exceptions), but in this particular case we have to bear in mind that it is a subgenre of yaoi, so we're still dealing with male on male pairing, with one taking on the "female role" in the couple, adherring to heteronormative standards. Since that is the case you'd assume that the delivery would be made from the rear. I recall some specifics where the omega develloping a womb is a plot point, but it's not always specified. Biologically speaking, the anus of those omegas would work kind of like a cloaca in the animal kingdom, I guess?
For this specific manga I'd say that vampires are able to change their biology to match their partners, and since vampires are more fantasy and magic than scientifically justified in general you can pass more bullshit happening, especially since it's not really an important point in this manga (as of yet). It's more focused in the relationship and dynamics between the characters, less so on the mechanics of how the races work and interacts with one another.
Vampires plot points are always about the conflict between the imortal being and the mortal one, and the guilt of wanting to turn them and shutting them away from the rest of the world, rarely about gender or reproduction (even though it happens, it's a plot point in "dance in the vampire bund", for example).
In general, it's fine to treat stories like this as normal romances. Even if you're not into yaoi, "traps" or "fembois" are engeniered to appeal to the male audience the same way a female character would, and while in most case it's the gender that drives some (most) of the narrative conflicts, it's not the case here. The "female" lead here as a dick purely because it's the author's preference, it has no bearing on the plot (as of yet).
In short, the yaoi part can be ignored, since it's just dressing for the main themes that are the relationships between human and vampires, and also the parent and child one.
All in all, for my part I enjoy stories regardless of content if I find them good and/or to my taste. Yaoi, yuri, shonen, shojo, seinen, josei, gekiga, doesn't matter much to me. Sure at times I crave a specific genre, and I do enjoy all kinds of pairings, but I'd say it would be a shame to pass on a manga you could enjoy simply because it catters more to a specific audience. There are fantastic stories out there that are confined into a niche that people would not read simply for one tag or another. On the other hand, I understand people having stuff they're bad with, but by default I say give stuff a chance?
As a little aside, omegaverse does separate its castes into a hierarchical order, it's just that it manifest physically as well. The power balance is also frequently upended, with omegas that are originally at the bottom rank so desirable that they end up enticing and wrapping up the omega around their finger. There's lots of kinds, some are like queen bees, others like princesses or idols, others still like the bullied kids in the class. It's important to mind the hierarchy in the settings, but all involved are lust driven, and most often than not are archetypes that obey their clichés, so it's not like the hierarchy really matters, since it usually only involve the 2 protagonists and the rest are just set dressing. You'd rarely find a story with several omegas as important characters, but you would have stories with more alphas to fight over the "female" love/lust interest.
Granted, there is a whole spectrum of degeneracy and expliciteness in all genres, and those are no exceptions, so I'd say there is something for everyone even in the confine of the omegaverse, or yaoi in general.