ok let me think…
keita- alpha for sure. the only time i would want him to be an omega is if yunseo is an alpha, like a subversive thing.
hanbin- i think he would have to be an omega but he would have a difficult time dealing with it at first. he probably feels a certain way about it
leejeong- this man is the definition of beta. at most he can be the right hand alpha?? but hes a beta
yunseo- i feel like its fun to play with this guy, he can be anything you want. i think alpha yunseo who comes out softer than the others is fun, beta yunseo unrequited love for an alpha and/or omega, omega yunseo yearning for a mate and a family etc
seungeon- i can see him as either a beta or an alpha. he isnt always the rowdy one or the one jumping the gun but he has his moments. he knows what he wants
munjung- alpha. its only been clearer over time lol.
jihoo- hmmmm idk… i feel like he may be a beta? i dont get omega from him but i dont feel strongly about him as an alpha…?

i dont have super strong ideas about any of their omegaverse sec genders and im open minded! im interested in public opinion. let me know how you feel about these anon!