OP your question is very broad. I'd probably only use Distilled water for extract since I have highly alkaline water.
For AG beers, I would mix my water with RO/distilled, and/or adjust depending on the amount of acids the dark grains add to the mash. (and while I'm at is maybe do a minimal adjustment of the flavor minerals as well.)
Ale or Lager has nothing to do with it. It's the amount of acidity that the grains add to compensate for the water minerals you have. Generally you want to target 5.2-5.4 pH in the mash.
Darker malts generally have more acidity and can counteract more alkalinity than can lighter colored malts.
Therefore, when brewing lighter beers, I generally either add additional acid, or mix with RO water to bring my alkalinity down some (or start with RO water and add a few minerals).
For darker beers, I might not have to adjust for pH much, maybe a small amount of acid.
Someone with less alkalinity might be fine for light colored beers, and may have to add stuff to raise the alkalinity to adjust for the acid the grains add.