TIFU by trusting the paint rep's mixing ratio on a silver Corolla

Had a silver 2019 Corolla in bay 3 at the shop off Highway 9 in Everett last Thursday, and the rep swore their new blend needed a 4:1 ratio instead of my usual 3:1:1. I sprayed the door and fender anyway, and by the time it flashed the metallic looked like a totally different shade under the booth lights. I ended up sanding the whole panel back down, mixing a fresh batch my old way, and eating 3 hours of comebacks while the customer waited in the lobby. Now I'm stuck wondering if I should've just trusted my gut or if the rep actually knows something about this new formula. Anyone here had a paint supplier push a ratio change on you, and did it work out or bite you?