I know its the main focus, but theres 0 point in not having a perma cage on him if hes not gonna use it ever. If they can go out of their way to change the male characters to futas, it cant be that hard to give the MC more options in how to act in scenes.
Well you're a bit too unfair about this whole Dom stuff. I mean there are tons of topping options for most characters.
Slime, Goblin, Brigand, Orc, Centaur, Dullahan, Harpy, Goblin, Warlock, Vampires, Dark Elf, Trudy and Kiryla. Fire Elemental, Mermaid, Angel and ghost.
Maybe you just didn't find them. Or didn't want to.
Also there is a permanent cage and personally i didn't like it :\...