So, when a girl reaches the 100 points of KP, she will call you 'Master', and become your sex slave, even if she is not collared?
After some time that I collared Bree and Sasha and form the home harem, I'm bored by be called 'Master'. I could say that I regret of that action (but not of the harem).
In my opinion, there should be a command that tell the girls to take off the collar or that they stop to call you 'Master'.
Probably the girl will lose some kinky points, and her KP bar will be unlocked, making the possibility to low or raise her KP, and when the bar reaches 100 you could gift her the collar or tell her 'call me Master', again.
As far I know, the harems require low KP on each girl to be formed, but if a girl has her KP enough low (less than 25), the harem will be broke.