I've been wondering the same thing recently, I noticed all the parameters can be adjusted to greater numbers than the default sliders. So if you are using the greyscale to Normal node, you can crank the Intensity to a larger value, like 50 or 100, this will make the gradient slope more apparent.
You could try the Normal Blend node to layer different Normal nodes that have different intensities, using a mask.
So with that grass example, maybe the glass blade could be propagated using a splatter node, then turned into a normal map + mask for a normal blend mode, layering it on top of a ground map.
Also been messing with the Normal Color node, it lets you define the direction and slope angle, so with some masking and blending that might work for flat angled stuff.
I'm wanting to create a cracked surface where each piece is slightly sloped in different directions, hoping to figure something out...