Reporting back on using dark meat....and using the roasted poblanos method.
I ended up using chicken legs with bone, as that's what I had on hand. The sauce was really tasty when I poured it on the chicken but the sauce started to breakdown and separate toward the end of the cooking time (looked really icky), maybe due to the longer cooking required to finish dark meat on the bone. Next time I'd go with boneless thighs (less cooking time needed), or boneless breast as the recipe calls for. I'm also dying to try the original recipe using non-roasted poblanos...will definitely be trying it that way soon.