I don't think vacuuming or cooking in this situation is being Mr. Nice Guy. I think it's being an adult and pulling your weight. It sounds like you have stepped it up in this area, so I'd keep that up.
JR, I gave this exact question a ton of thought when I was spending 2 hrs this weekend in the 100 degree heat doing yard work. I realized that I'm not doing it for my W, though she may perceive that, and that I'm doing it bc I realize it's my responsibility that I'd been shirking. I think so long as you are not doing it to get "brownie" points with the W, then you are on the right path.
I love how Rose put it as "being an adult and pulling your weight" and I 100% agree on keeping it up. Thanks Rose!
Me39 M11 : T13 D9 BD 5/31/16 In House S until 6/21/17 Divorced 10/5/18