I don't really think D/s itself needs mechanics, personally. It's more something that characters, or the player, impose on a game's sexual mechanics similar to a character's personality traits. All the other mechanics need to come together to give the tone of domination and submission, although the whole 'evoking the feel of being a domme' thing is waaay harder to do in a game, I would say.
If pressed, I would say that the Dominance/Submission bar pretty much only works for switches, and even then, badly. What it otherwise works for is people who like temptation, which isn't necessarily a bdsm related thing at all. The idea of a thing getting more and more tempting can be a powerful concept. See also, corruption/sexual liberation, which are, again, not reeeally BDSM in and of itself but can be part of one's fantasies relating to it.
Part of that has to do with the public/porn perception of dominance and submission being so fucking skewed. I swear to god, some peoples' understanding is literally 'man chokes woman, woman likes it'. It's also been heavily conflated with what I would call 'rake fiction', after the character archetype of 'the rake' which is a suave, sexy, seductive man who wants to rip your bodice and take your pure, pure virginity so you'll never be clean again. This emerged, for pretty legitimate reasons, out of women's erotica in the 1800s, and has lingered in the background of public perception of BDSM ever since. At some point, the Japanese started reading these, and someone had the bright idea of inverting the dynamic, and that's how you got Monster Girl Quest, a game about rape, but tagged as 'femdom'. This then makes its way back overseas via the eroge industry, and we start making our own inspired by those, and someone makes Tales of Androgyny based on that mold,
Basically, I would say the main mechanics one would need are... some form of ability for characters to voluntarily submit themselves because of what they want, actively, and if the player is dominant, some way for them to make decisions about the ensuing scene, and probably some form of 'pleasure' vs 'too much, nope' bars for the submissive. You don't have to simulate negotiation, necessarily, though that might be fun for characterization. Also, aftercare is never shown in games, like... ever. So do that, because appropriate aftercare is a really important part of the dynamic and can be incredible for characterization. It could be cuddles, or it could be a round of Mario Kart, or really anything the characters do to relax each other afterwards.
So if anything, now that I think about it, one of the ways you could evoke the feeling of being a domme would be very similar to the way cooking/crafting minigames are often done, where you add materials at certain times, and try to make everything fit in the pot, and not let it get too hot or too cold... except the thing you're crafting is an experience.