My point is that you are not reading the novel, and are injecting some weird thoughts into it.
We're actually making the very same point to one another - I think you are projecting some weird personal thoughts into it. I suspect - but don't know - that you sympathizes with the MC when they are not intended to be a sympathetic character.
(and that is normal for people to disagree on interpretation)
The MC is a monster wearing a nice guy mask. Lacey knows this but loves her shark anyway because she is an abuse victim. And she is specifically a type of abuse victim that turned to self abuse as a defense mechanism. Her desire for punishment is crazy but it's who she is.
How do I know this about Lacey? Two reasons supported by the text - one, Gristle's rules. Take away Lacey's pencil's on Friday or she will stab herself with them over the weekend. Two - the pain she received in college actually healed her. Were it not for Isaac she would have freed herself of the images of her father.
Now - this is indeed personal - but I dated a cutter once. This is the psychology of the cutter:
Achem. Life gives us all sorts of bad feelings that are hard to identify and/or impossible to deal with. Job, traffic, painful memories, relationship drama. Sometimes there's no solution. What if we could actually solve all those problems all at once? What if we could just cut them away? Cutters transform diffuse, amorphous psychological pain into physical pain. Do they like it? Kinda-no. What they like is that they can literally release all that pain by transforming it into just a few cuts. Razor blade goes in and then you only need to deal the physical pain - and they know how to heal or tolerate physical pain. This is what Lacey was doing with the pencils - making psychological pain physical.
(Lacey is also a masochist and a scapegoat - but I'll address that separately because they aren't the same)
Why do I think the MC is a monster? So many reasons! Replay the King's Day scenes - when Gristle is asked to come up with his darkest fantasy he comes up with three rape fantasies. The player MUST choose a rape fantasy for the MC. The player then MUST choose a mind control fantasy that
destroys the minds of the harem members. Anna gets to see what only Lacey has seen up until now - there is another side of Gristle that Anna has never seen even (if she accepts it in some way) As Lacey says elsewhere the MC is her Frankenstein monster - but he is a monster.
I will eventually collect lots of quotes to support this theory for you and anyone interested.
And of course the final sex scene of act 1. Lacey and Frankenstein have the best sex they've had since their wedding night. He almost kills her and she almost dies.
As to you quote: ". . . .I'd still understand, but I might feel like we should set a time limit for how long you punish me."
Lacey is telling herself that - one day she will be healthy. I'm rooting for her but that doesn't mean that this sick puppy doesn't crave the pain right now. (again, when I have more time I'll collect more evidence)
You don't have to change your mind, you are set in it and are clearly enjoying yourself with your own "interpretations", but please stop trying to push so hard on it.
For me exchanging theories is the fun of this game. I hate the sex scenes so much. And I do think people are interpreting it wrongly. So I can't promise that any more than you can.