Thinking about memory as a form of control in HtN. Because obviously Cristabel and Alfred and Loveday don't appear in the story, they survive only in the memories of the people who ate them. And remembering a dead person is an act of control, because memories are not objective. Someone's perception or memory of another person will never be entirely accurate, it will instead be their own version of the person. Even if someone loves you - perhaps especially if they love you - their idea of you will be influenced by how they want you to be, and there will be things about you that they have never seen or noticed.
If you are dead you no longer exist as an individual person with agency and an internal world; so the image that living people have of you will be superimposed over the person you actually were. You are no longer yourself, you have been made into what other people think you were or want you to have been.
And of course this is particularly relevant when it comes to the cavs. Someone consumes and destroys you, and then they commit a final act of violence and control by replacing you with the idealised or demonised picture that they have of you in their head. The narrative itself participates in this violence by erasing you and prioritising your consumer - they appear in the story as a character, whereas the readers know you only through their descriptions and memories.
We also see the memory-as-control thing pretty explicitly with Nonius. He shows up speaking differently than he did in life because that fits with Ortus's image of him as an idealised epic hero. It's not clear how much of his ghost is actually him as he was, versus the version of him created by Ortus and the Ninth after his death.
I think it's significant that in order to preserve Gideon's actual existence, Harrow has to remove her own ability to remember or perceive Gideon. Harrow stopping herself from being able to create her own image of Gideon also stops her from consuming Gideon and entirely destroying the person Gideon was. The lobotomy protects Gideon from the violence of being made into a memory, and so it protects Gideon from the violence of Lyctorhood.