I don't really think every encounter necessarily needs a sub/dom option. Both mindsets are fairly specific kinks, remember, and the dynamic as a whole doesn't really make sense in all sexual situations.
For mob win/loss (unless the mobs themselves are specifically angled towards subbing or domming), Steele being a sub/dom would be a hard sell. There's give and take on both sides, and the mob in question suddenly becoming a dedicated dom to play along with Steele's submissiveness or becoming a compliant, order-following sub out of the blue would be weird (if they're that subby as to trust a total stranger so completely, why'd they even fight you?). Just laying down and letting yourself be used is not necessarily submission in the sense of the kink itself, just like forcing yourself on someone else is certainly not a good definition of domination. That's really just rape.
NPC's are even less universally compatible, simply because being a sub or a dom is a pretty major character trait. If they aren't written as such from the outset, tacking it on runs the risk of breaking the character and weakening their personality. Going even further, making every BDSM-inclined NPC a switch is a less than ideal option from a creative freedom standpoint, despite the fact that it would let players always be able to control whether they dom or sub.
In my opinion, sub/dom scenes and themes should be mostly kept to NPC's or mobs specifically designed around the kinks. Otherwise you run the risk of misrepresenting the fetishes and/or just being sorta "wait, what?"
Firstly, I should have been less lazy and elaborated that when talking about being 'dominant' or 'submissive', I used the broadest possible definitions, instead of talking about specifics of relatively well defined kinks. In that sense, everything can be viewed as a powerplay and in every aspect of their behaviour and dialogue PC can have Alpha or Omega options/tweaks.
Then I should have realized that OP probably
had talked specifically about D/s kinks and deleted my comment as pointless, but whatever :/
As for the established characterization of mobs making the presence of dedicated options and/or tweaks for both submission and domination 'a hard sell': for any non-static enemy it can easily be handwaved by them being a different individual every time, and for all of them by spess-magic-drugs that they or PC excrete. In any case, the game already kind of does that for a decent amount of fights, e.g. Zil.
Fully agree with your point about NPCs, with a small caveat: tweaks of PC's reactions and behaviour can be a welcome addition, at the very least in some cases. Even though, IIRC, Nonesuch stated that he doesn't particularly like the existing doc for enslaving Sera, I personally did enjoy it specifically because of the unruly sub uspects.
And if it's wired up properly, the score system is supposed to be self-regulating, and certainly not restrict PC's options or force them into anything outside of those specifically D/s oriented NPCs.
Tbh for all the success of TiTS thanks to its incorporation of a huge range of kinks, I suspect subbing/domming is delivered much more effectively if the game does one to the exclusion of the other. That way a player knows what they will be getting going into it, and it can be explored and delivered far more effectively.
It may very well be true for the audience that is seriously interested in and/or practices those kinks.
For a schmuck like me who doesn't model their PC after themselves, doesn't associate themselves with PC during sex scenes and has only a passing interest in BDSM, TiTS model probably works better.
