That's what I was thinking as well (on a sub path only, of course). Kane has been treated like shit (evil Olivia ftw) and saw how Seth was abused, and yet he never even has an option to speak out in defiance. Well, that's not exactly true - he can be a little passive-agressive towards Olivia, but he never shows any real defiance and doesn't even have inner thoughts about killing Olivia.
Granted, maybe he enjoys being a worthless slave and really is too much of a pussy to have a backbone, but an option for him to reflect in his thoughts on his current predicament would go a long way, imho. Something like: "Do I like how Olivia treats me?" and "My sister is truly gone, only Darth Olivia remains. I'll try to find a way to end her for what she did to us (me and Seth)".
Wish he could find his inner Spartacus and make Rome tremble! Burn them all!
Even on the dom path such inner thoughts would add to the immersion and help shape our protagonist, give him some agency.