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A rice cooker just heats the rice mixture up to a simmer, and as soon as it senses the temperature increasing (meaning that the water has all been absorbed, or evaporated), the temperature goes down much further, so it just keeps it hot, but not burning the rice. There used to be a bunch of books with recipes using them, which didn't really do very well, because you couldn't brown the foods in them. With your Instant Pot, the "rice cooker mode" is on pressure cooker low mode, for 12 minutes, then it goes on that low mode, to just keep warm. If it's a newer version (mine is the oldest kind) it might have a simmer mode, that you could set, after sautéeing the chicken, and other things, before adding the rice and liquids, then cook for 20 minutes, then let sit for 5 minutes, then check the rice. You can also do this in a Dutch oven, or something like that, making sure that you don't cook too fast - at a slow simmer. Good thing is, thighs are hard to overcook, like breasts would be.
