Grass node interpolation method expose

I'm trying to use "roads"(splines) to place some "grass" in the world (I'm using quotes because they aren't really roads and they aren't really grass, haha, but they use the Grass node and are Grass as far as Unity is concerned). You can see from my sample that some areas the grass objects are getting placed about as I'd expect, but in other areas they don't show up at all even though the texture gets placed from the spline. I can increase the Density field of the grass dramatically but that just puts more grass objects in the places where it's already putting grass, and mostly still doesn't put any in the other parts (although an occasional clump might appear somewhere that there was formerly nothing if I turn up density ridiculously high like 100). Can anyone think of a reason my Grass box would only be placing in some areas not others?

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Brian Reynolds — Today at 03:07

OOO, it's this code right here in GrassOut -- my narrow little roads are narrow enough that it often just gets wiped out to 0

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[03:08]

@Denis suggestion that the interpolation mode (and whether any at all) might be a good configurable switch for the box in future version

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[03:09]

Same view (more or less) with the interpolation commented out: