I have used Testors Dullcoat spray for decades. I don't think yellowing is an issues UNLESS...
1) you are putting it on a white model where the yellowing will be noticableUnfortunately the paint color of choice is gonna be white.
Is there anything out there that'll work???
I never said it couldn't or didnt yellow. But its not a huge issue unless you are building a white model or glop it on thick. Period. Its not believing its KNOWING from use and experience with the product since the 70s.You can believe whatever you want.