Even if it's a soft aspect, Saturn can cause some damage (nothing excessive) but I won't bother it too much, just always keep your AoP high.
Saturn aspecting the AC is similar to it aspecting the Chart Ruler but with less intensity.
With hard aspects I would say it can be just as bad as Saturn on your ruler, maybe a bit less. But in this case it's different since it's a soft aspect. I agree with Hs66, just be more careful than usual, that's it.