It really depends on the lens.

Scratches. On the one hand, I have a 210/5.6 Zircon with a horribly speckled front surface. It shoots well. On the other, I have an 80/2.8 Xenotar whose front and rear surfaces have the classic "cleaned with coarse sandpaper" look. It is very soft and horribly flary. Stopping down doesn't help at all.

Separations. On the one hand, I have a 58/5.6 Grandagon with horrible separations. Rings of fire in both cells, silvery spots in the middle of the rear cell. It shoots well. On the other, I have an EKCO 25-15 wide angle attachment for the 25/1.4 Cine Ektar II that shows strong Newton's rings (really Newton's stripes) from one edge to the other. They're very visible in footage shot with it.

It depends on the lens.