My goodness, I've written so much about this but it might be the first article on this topic I've read that was written by a man. My partner was a stay-at-home dad from the time our daughter was 10 weeks to 18 months. I was more or less a full-time caregiver on the weekends so he could focus on school work. The experience *really* opened his eyes to the realities/demands of caregiving. And he mostly focused just on baby-related care. It's not like I returned home from work to dinner on the table or folded laundry in my drawers. He absolutely cannot believe how many women throughout history have cared for not just one child but multiple children while being responsible for all other household needs -- seven days a week!
Two things I would add to this -- the division of labor is not just about chores, but also invisible/emotional labor, which can be *so* hard for a partner who is not doing it to understand.
And... I slightly disagree with your last statement: "This will start with women demanding nothing less than an equal (50%) partnership in all things household – being a partner, being a dad, and being all in just like they are." Yes, we need to demand this, but in many cases, we *are* demanding it and simply not being heard. (That's why women initiate 70% of divorces and college-educated women initiate 90%!) It *really* starts with men like you speaking up. The sad reality is that men are simply more likely to listen to other men. If any man ever wants to understand how to be a true feminist ally, I hope they will follow your example.