I have it in my mind that Omegas have a say in the Mating process. Any Dominant must provide Courting but only after an Omega asks them to Mate them. Any Dominant could ask Omegas for consideration and only until the Omegas ask (verbally, signed or written) should any Dominant undergo Courting process.
Omegas can ask any Dominant their inner selves are going crazy about (they have this Insistent Urge to do it) to Mate them and can have up to any number of Mates their inner selves could want as long as all their Mates are agreeable. A lot of Omegas settles for one, as previous norms were hammered to their cores. There were cases where an Omega asked their whole pack to be their Mates. The highest number of successful Mated Pairs were 15, where the guardians of a Mafia Alliance were proposed by the Boss himself. The most common in Japan were Mated Pairs of three or four.
Contrary to popular belief, it's not detrimental for an Omega if they were rejected. They'll just go through heartbreak, lots of ice cream and move on no matter how hard it is. (Exception to this are Yanderes)
Courting Process can take as long as years until everyone in the Pack accepts and the Dominant/s have the blessings of the Pack Parents (in some cases, biological parents too). They offer Omega gifts, and can only touch the Omega with their consent, in some cases offer a dowry to the pack. Dating is the stage where the relationship between A/B/O pairs are explored. From handholding to sexual intercourse. Every base is covered.
It's only after the Bonding process can Omegas or Betas get pregnant during their heat. Contraceptive pills for all type of Submissives are created with no lasting side effects. There's a research on Bonded Mates that with a compatible and lovefilled connection, telepathy is possible. Bonding process is equivalent to marriage but in a more permanent sense.
Alphas are the strongest and a dominant through and through, the urge to protect and provide is what made the Hero Society swarming with Alphas. Dominant Betas usually only exert dominance to their submissive and are the most common of the lot. They live their lives normally, with no slick and heats and no knot and ruts.
Submissive Betas are rare but not that uncommon in Japan. The Prime Minister's mate is one, after all. Betas can only be submissive once they surrendered to their Dominant Mates. They only submit to them and could dominate omegas as well. They undergo heats that lasts up to two days and produce a small amount of slick compared to Omegas two times a year.
Omegas are more fragile than the other two but only because of their heats. Outside of their heats, they can be one of the strongest, too. A number of highranked heroes are Omegas after all. They undergo heats twice every six months that lasts up to five days. Every omegan heat is different and so researched about it vary for every country.
Male Omegas are the rarest out of the bunch. They usually disguise as Betas so as to not incur an Illegal Bond. They still produce slick during heats and their bodies undergo change once the Bonding Process was commenced.
A Pack isn't build, it finds itself. After the events of USJ, the realization that Class 1-A is a pack is when their Pack Mother was beaten down by a Nomu and all of them went to protective primal modes. The Pack Alpha was known when Katsuki was kidnapped. The whole class were feeling empty, hopeless and basically cannot be comforted until Hizashi and Toshinori arrived and calmed all of them down. It wasn't until Katsuki came back that everyone had the realization who their Pack Fathers were. (In my Class A, Shinsou Hitoshi Replaces Mineta Minoru)
Katsuki is the Pack Alpha, Izuku is an Alpha, Eijirou is a Submissive Beta and Shouto is a Male Omega.
Their pack is Class A, their Pack Mother is Shouta and their Pack Father is Toshinori and Hizashi.