Every dealer is different.
My old Ecoboost Mustang, they told me to unflash her, and when the Intercooler caused the AC condensor line to bust, they just charged me to fix it, no "Voided warranty", just here we go, good as new
from what I hear, @Fast Intentions Inc. is working on them (actually spoke to them)
no eta, but they are being developed. Rather have a catless or hfc downpipe that a catback or axleback, I want power, not a fartcan