nacho, coparenting, etc

For those who do nacho, how have you guys gone about successful nacho while living in the same household and being around SK, when you might strongly disagree or see how badly they are being parented or behaving?

Is there a way to get to a point where it doesn’t affect your home peace and your SO relationship? I am hitting the year mark of living with my SO and SK with us half time and we cannot seem to find a good balance.

I need certain rules and boundaries in the home I share to keep my sanity with SK because my SO is really laid back, so we have been “coparenting” in the sense of just in the home, then I’m pretty much hands off in every other aspect outside of our home because of HCBM - but I’m here seeking some perspectives because it’s really not working.