I just picked up my new ST last Saturday with the black 21 inch rims. I am going to try out the Kumho wintercraft snow tires on these rims, them find a rim hopefully equally as hot to put in the Pirelli Scorpions come spring.
This is the approach I took with my 2014, 2016, and 2018 Explorer sports as well, where i would put the winter tires on the stock rims, then would run 2 Crave no 14s in the factory rubber come summer. Makes for a quick switch each season.
I was hoping to perhaps be able to use the 2 craves as my winter rims going forward, but indeed was told they would not fit the 2020. Oh well will sell them and the summer tires to fund the next set of custom rims.