The Chinese don't do 100 hours/rolling 30 days. They do 100 hours in a calendar month. Working 4/4, you can work a LOT of hours in the 4 weeks on if each calendar month has 2 weeks in it.
I think most of the airlines offering this expect you to be "flexible" about when you do your sim sessions and medicals. Like, perhaps, right in the middle of your 4 weeks off.
They are paying you a bunch to work 4 weeks. They are going to squeeze every single dollar out of you.
When I was at BCA, I was 6/2. They now offer 6/3. The flying was efficient enough that you could probably work 6/3, and get well over 900 hours a year. That would be 250 hours of overtime under their current contract offer.
4/4 I don't think I would like because of my above concerns. But everyone has different priorities in life.