I moved to MO in August 2018 from a home and job in Illinois to start my job in MO and live in MO. It says that if I chose part year resident that it'll tax my entire 2018 income of already taxed IL income. While it says if I chose resident that I'll receive "credit" for my already paid taxes, I have yet to see any fluctuation or application of said credit. It seems that if I chose resident then I'll get double taxed by two high taxing states on my already small amount of earning.
