For top.omegas in omega x alpha pairings:
https://www.mangago.zone/tag/Top%20omega/
https://www.mangago.zone/tag/Alpha%20bottom/
Ones I suggest from this/ones I liked:
Both have content warnings though
https://www.mangago.zone/read-manga/a_tough_alpha_wants_to_be_loved_cornered_by_a_young_omega/
(Dubious consent)
https://www.mangago.zone/read-manga/katenkouru_ni_wa_mada_hayai/
(Past rape/SA for one of the main characters with outside characters/dark past)
The one fluffy/smutty top omega read is The doujinshi: green light, no red flags!
https://www.mangago.zone/read-manga/yuri_on_ice_senjou_no_hito_doujinshi/
Bottom alpha x top beta:
Like these ones a lot:
https://www.mangago.zone/read-manga/oblivious_mr_b/
https://www.mangago.zone/read-manga/kakumei_no/
Hi is there omegaverse BL manga with omega seme or alpha uke?