Wait...
I can totally see him doing this. Laplace was his daughter so he had an easy time brainwashing her, and when she went too far he dumped her.
And the kingdom is clearly dependent on him now, so he can easily groom the royalty into letting him use them as his new guinea pigs, possibly the princess has been his research tool even before she was born.
Hell, he has probably been trying to turn the royal family into "second" Laplace for generations.
But...
Why was he so protective of her during the tournament? It would not be because of his research, he could always use another guinea pig - like he did with his daughter.
I'm having terrible thoughts about this.
Thoughts like he is gonna pull an Orochimaru and jump his soul to a new body, a body he is not able to change into what he needs (else he would just change his own) so he wants to create it from scratch the way he wants it... and the princess is being primed to create that body for him, giving him not just a "perfected" body but also a body with political power (at least, even outside his own country).
That would explain how that society became so misoginistic (besides fear of a second Laplace): he is doing his best to make people think of women as just good for breeding tools so no one has any issues with him actually using one as such.
That said, I'm hoping I'm wrong. As terrible as Maxwell clearly is, that may be going a bit too dark for what we got until now from the story.