He is a dominant omega, they are often mistaken as betas. Since when tested the result is beta, and they have controle over their pheromones. They are extremely rare. A dominant omega is dangerous to dominant alphas if it's not more than five. Because they can knock them out with their pheromones/ gives them a pheromone shock, can force them into rut. But dominant alphas are after them, see what happened to Keith Pittman's father, he was sold to 5 dominant alphas families, so it's better to hide it.
The Miller siblings father is also a dominant omega
I don't remember, I read it years ago, but probably not because Dane is not someone who would talk about it, and it would be dangerous for him if the wrong persons found out. But the author listed her planned stories several years ago on twitter/X, and in the case of "Desire me if you can" also the pairing and their secondary gender.
There are actually more things on the dominant omegas. They can hide their uterus. They can recognize each other. And they could reach for the other? Help the other heal? Because one did that for another, also the pheromones of that one also helps his dominant alpha's mental health. There is also a story I didn't read with another dominant omega, so don't know if there are more informations.
And Grayson is like the dominant alpha in Stewards lab, he was born manifested, releases more pheromones and has mosterous strenghts.

MF IM MANIFESTING GRAYSON GETS AN ALPHA WHO PUT HIM IN HIS PLACE