So, I eat quinoa and potatoes but have paleo and grain free also listed.
I personally need more carbs than paleo allows. I'm an active person and I'm going to do what works for my body. I get over loaded by protein and fat on strict paleo and need a higher calorie diet somehow. So I eat paleo dishes on top of potatoes and quinoa a lot. So yes I am Gain free and I don't consider quinoa a grain. According to my research and the fact that my body has no problem with it I consider it a seed or fruit of the plant. So if you don't want to eat quinoa or potatoes, don't. You can use cauliflower instead or whatever you want, I'm only here to suggest and tell you what works for me. I adapt other peoples recipes for me so you do the same for you. Please pick and choose.
P.S. When I went grain free I did not eat quinoa. I added quinoa in later to get more diverse nutrition.