How much screentime has Kat actually got? What can we confidently say about her personality? Based on what we've actually seen, we can pretty much only say that she's sexually inexperienced (even her sexuality is up for the player to choose). How would she actually react if she were put into that situation? I think there's plenty of room for things to go in a lot of different directions.
(But don't think about it too hard, it's just my bad fanfiction that I wrote.)
I don't mean to be condescending here, but here's a very basic thing about how stories work: Audiences come into a story expecting to be delivered promises that the writer makes to them. Some of these promises are delivered directly by advertising, some of which are delivered by events in the story itself, and some of which the audience brings with them due to genre expectations. This is why so many people ask about when there's gonna be Katherine content and are surprised when the answer is "no", because the erotica genre, especially WEGs, have the basic audience expectation that if a character related to the protagonist is introduced on screen, there's the implicit promise that there's gonna be incest with that character later. You'll notice that in games where there isn't gonna be any incest, the main character's family is usually nowhere to be seen. And it's not like incest or lesbian content is off the table in this game either.
And in games, some of those promises are delivered by the mechanics and the UI. In this case, if there's a stat the game tracks as you make choices, that implicitly promises to the player "Hey, this number is gonna be important, there's gonna be a choice later where you need this number to be high enough to get to make it."
Zorlun has talked about this in the past and says their philosophy is to add every stat they can think of, in case they think of a use for that stat later, without having to go back and modify earlier parts of the game (and force to to start the game over). And that's understandable, especially while the game is in an incomplete state, but it *is* very weird there's all these affection stats for characters who show up once and are never heard from again, as well as kink and personality stats that don't actually do anything.
tl;dr My response to your point of "She's been a submissive her entire life, why would she change personalities" is "The existence of the Domination stat implies Myriam has the potential to become a femdom."
I don't really want to weight on the debate here, but I think I should address a few things.
As stated in my previous message, the game is very experimental for me, it being my first game, so there is a lot of things that I learn as I go along, and I already see some things I would have made differently, and will do next game.
For example the 'love' stat for a few characters is not about love at all, but just here to gauge the will for some to help her or not, for some I put a stat but will probably never use them, since as characters pile up as well as story lines, I prefer concentrating on some putting some others aside, but most should have their use, it's just a question of time.
On the stats subject, a lot of time I also prefer put some in advance for use later on, even if I'm not sure to use them, because it's far more simple to add something from start and not use it than the opposite, it's way more complicated (or annoying) to add a stat (or a variable) back earlier in game because now I need it (the reason why some times I make everyone restart the game or roll back, which nobody like doing).
For the characters, be it small or big roles, they are all only here to play or emphasis on one of Myriam's side of her personality or some times to be a stepping stone (like Anthony who was one of her first ordeal and step to freedom), which is one of the reason I don't want to go too deep into naughty scene of other characters like Katherine for example (it can happen, but it will generally have a parallel to Myriam later on), the game will always be about Myriam.
For Katherine, I keep repeating myself again and again, but she has a very important role with Myriam, true filial love, Myriam and Katherine are everything to each other, and whatever happen in life, they know they can count and the love and support of the other and this is meant to be one of the constant of the game, one of the anchor of happiness and stability in Myriam's life. So, NO CORRUPTION!
BUT, that doesn't mean no naughty business, as stated a few times as well, there is in the book a little triangular action between Myriam, Katherine and William, that I had in mind (I want to do something as well with Jenny, but it will be more complicated to bring on, but will happen depending on the choice made for Katherine's sexuality).
I would add as well, that it's not because a way of doing things happen in other games that it should or will happen the same way in my game, after all if I made my own game is in the main part because I wasn't happy with how things were going even in the games I liked... I'm not doing my own thing to do like the others, no point in that (in my eyes), which is one of the big reason I didn't touch any adult game since I started mine, I don't want to be influence more than I was already.
Of course, that doesn't make my ideas or choices better than other developers, but even if I make bad choices, I need to make them to see and understand why, we're coming back to the experimental side of the game, if I want to learn, I need to do my own thing to learn and get better, by trial and error.
But it's becoming a wall of text, I'll stop the monologue here. ^^
I just hope it can help clarify some questions on how I do things or think.