Yeah if they can get them to you cheap I’d definitely pick those up just to test fitment.
Also, you could do some part number searching and checking to see what cross compatibility there is between different models. For example, we know that Audi S3 spindles are the same as a few other models (CC, Passat) and this part bolts up to our cars. If that part number matches those and the wheel bearing/hub assembly matches then the S4/5 stock rotors *should* work.