I’ve had some pretty great results so far with generating my terrain and dynamically placing road decals as needed.  The Easy Decal 3D solution ended up being pretty great.  The folk at &u Assets were super-helpful, and with clever use of their baking and decal combine features my roads went from 20 fps to 200 fps.  So, basically solved, and it’s worked out pretty well for putting interesting terrain features when staring down at splat-mapped Unity terrain starts to get tiresome.

I feel pretty good about the look and feel of my overworld, as well as the scale (which was a concern since it’s extremely exaggerated, even though I wanted a gritty feel).  I still have a ways to go before I can finish up my core loop and release a build, but things have leveled up a fair amount.