Tim mentioned the Fiesta ST brakes in one of his RS prep videos, so it isn’t just rumor. I assumed that meant rotors and calipers, not just calipers.
I’m interested to see what you come up with. I have an RS specifically for Rallycross use. Running the stock class now, but I may move to a class that allows gravel tires at some point.
Have you contended with the ice mode/brake assist issues, or are you thinking that less capable brakes will help minimize their affect?