Well obviously it blocks you from scenes with Anthony, because if Myriam makes dominant choices she gets rid of him early in the game. Anthony is part of Myriam's sub route. He's a Dom male, and having Myriam be dominant is incompatible with what he wants.
Having said that, although you can make Dom choices for Myriam, that doesn't mean she becomes completely dominant. And it doesn't mean that she can't take part in sex scenes. But if you make only dominant choices for her, then yes she's going to avoid a lot of content. But it is possible, to have Myriam's Dom score higher than her sub score, and still have her take part in a lot of scenes, like the gangbang at the museum, and the threesome with the two cops and also with Cassius. But that means that sometimes you have to make some sub choices for her
If you had her stay with Anthony and take part in the Party he organised with his work colleagues, then Myriam's sub score rocketed in the early part of the game, and she becomes a confirmed submissive. Later it's possible to increase her Dom score, because now she's not under Anthony's influence anymore, she's in a position to make more Dom choices if she chooses. But nowhere near enough to ever get near the high level of submissiveness that she already accumulated. If you don't dump Anthony as soon as you can, then Myriam is always going to be mainly submissive.
So yeah, if you only make Dom choices then Myriam will miss a lot of sex content, because those scenes rely on Myriam acting in a submissive way. But you can still have her with a higher Dom score than Submissive, and have her take part in those scenes, by allowing her to make the Sub choices which usually lead to them. That results in her having slightly more Dominant points than Submissive points.
