So, just thinking about this long term, how would the blending of parenting styles impact these 3 kids? Let’s say Doc continues to adhere to parenting her son as she chooses and you parent your girls in a very different way, as you choose. And the three kids are watching all this.
When he has to dustbust the crumbs and the girls do not dustbust theirs, what is the impact on these kids, their relationships to each other and to you two? Sounds to me like there are two totally opposite sets of rules and ways of thinking.
As Andrew pointed out, these issues are tougher with young kids. You might want to look more into perfectionism, its root causes and its impacts. Like it or not, your daughters will be heavily exposed to it when with the Doc, even if it not directed at them. But, eventually, it very well might be directed at you and them as she does it to her own son.
Me 41, H 47, M 15 yrs, S11, S13 BD 1: 11/4/14 we work on it; really I pretzel myself BD 2: 3/31/15 H goes down to "dorm room" 8/15: H back to MBR 10/15: H back in dorm room 1/18: H files, now divorced