I'm scaling a testing application for ETBv4 as features are added to the game to test those features appropriately. It's called ETB Showcase. Right now it's nothing more than an alternate view that displays the maps without the player, FOV, LOS lighting and other visual obstructions. The showcase map feature itself will be altered to allow scrolling as maps will potentially scale way beyond the simple 51x51 map size that have previously been known to show themselves in the game series.
The map generation type is Diffusion Limited Aggregation. I favor starting development on this type because it's erratic and helps test FOV much easier at the edge cases.
An emphasis on variety of environments make colors an import part of the design in ETBv4. This also means that unit testing can't just be ensuring code passes all tests, but that when a color is altered or a design element is moved it doesn't skew or alter other features of the game as they're so tightly coupled. Because of this, a view model is imperative in establishing test reliability of these newer features.