After the pull request I rewrote the code based on mbrotz and immortius comments. I plan to use little sliders for each variable (ForestGrassDensity is working below). I had a good laugh trying to implement chuck size before realizing what immortius and mbrotz knew immediately (that it should be final). Sample rate seems rock stable and useful, but I decided to use drop down to control the choices.
Now the setup menu button ONLY appears when you select "Perlin with setup" Map generator. I am happy that the system is now only taking what the engine gives and on top of that I started a new map generator. So the whole code base really stands alone from the engine code.
I am headed on vacation and might have some time to look at things while I am gone. If I do I plan to read the code (and commit comments) to see if this system could be modded or not. Something like map gen setup might go either way.
Not sure if map gen setup could evolve to be our version of a map editor/map development system but that might be possible. Other questions arise such as why 2 menus are needed (map gen already has everything the map create menu has with the exception of the map gen selection pull down). Anyway Ill work on another pull request.
Lastly I like the vision you have for a stable engine supporting the mod community. Longterm when I will move on from this map gen thing, I will glad to help with whatever needs done.