I wanted to follow up with my question to what I realized is my larger question.
I'm currently plowing through Mutant Year Zero. I've fallen in love with the mechanics -- and even before finishing I've ordered the deck and the maps/markers.
One of the things I love about the mechanics is the risk of consequence when someone pushes a roll. It isn't just a matter of "And then the GM hits you with something" if you fail. It's that you can take a risk and push knowing you might well concretely end up pushing yourself so hard you hurt yourself, or you valuable gear gets damage. The GM is going to hit you with a problem if you fail. But even succeeding can come at a cost in MY0.
I really like that.
I also like that there are four attributes, each managed the same way in terms of tracking, each handled the same way in terms of dealing out damage, and each having analogues for healing.
Now, I am right now skimming Coriolis. And while it is only a skim, it already seems different from YM0 in ways I don't find as appealing. In particular the risk of pushing rolls is missing. I understand the risk in Coriolis is shifted when pushing with Icons. But this means that the risk only really kicks in when tapping a force larger than yourself. For me there is a different in this I don't enjoy as much. The task itself is not being pushed, the tapping of a supernatural force.
All of this is to say that while you cannot be beholden to Coriolis, know that you have an exceptional game engine already with MY0 and I would really love it, as you think the rules thorough, you don't worry about making sure it is different from those rules. Change them, yes, make them more specific to the genre and setting, yes. But the element of risk of the hero pushing himself harder in MY0 is so solid as is... i really recommend you stick with that if you can.