Hello and happy new year, mike!
nice job there. I am also currently developing nearly the same kind of plugin, like you do. I am doing this for my bachelor thesis and as i saw your post i had to take a deep breath. I hope this doesn´t affect my thesis in any negative way (well i think i should meet with my professor soon 
). I also wanted to publish my plugin by using the marketplace when its ready(near march, i hope our both plugins wont conflict with each other). i haven´t looked into your code yet so i cant tell how far you have gone already or how much more you want to achive, but the scale of the generated world is really, really impressive.
my plugin will also use some heightdata to generate a heightmap and i am deforming the landscape when i spawn roads, houses and rivers procedurally and so on. my focus lies on generating near game-ready levels so that in the near future i have playable procedural generated maps for my game i am working on.
long story short, you did great work there, and i can´t wait to see some more progress
– Jerome