Instant Time Check and sub boneless breasts

I've made a version of this in my own Instant Pot, and I generally opt to go for 20 minutes. It doesn't hurt anything to go longer, but the potatos and carrots will end up really soft and overcooked for most folks. Since you would eat it spooned over rice, that's not a problem for most Koreans, and they actually tend to like it that way. So far as using boneless breasts, or any boneless or skinless parts, you can, but it won't be as tasty. The bones give up a LOT of flavor in the stew and unless you have a really fat chicken, there won't be an overload of fat. That fat also helps carry flavors from the chili, garlic and onions into the other ingredients, and without a bit of fat that really doesn't happen very well. If you want to use chicken breasts, I recommend you leave the skin on, especially if you opt for a boneless version. You can peel skin after cooking, but at least you have the flavor addition. And some help preventing dry breast meat as well.