For a re-shaped terrain, my preference would be to form a new mesh and UV-unwrap it, to avoid the texture stretching/shrinking issue. Those could be released as replacements for the "stock" construct, or the terrain might be simply overlain on top of the construct ground.

I'm using a networked Vue to render the skies. The choice of atmospheres is intentionally the toughest ones to render, which many folks would find impossible to render for themselves. This morning I'm waiting out a slow sky render because I forgot to Alt-X and purge accumulated data before I began the render yesterday morning; that causes Vue to run slowly. My machines are only showing 5%-18% processor activity.

For city skylines and forest treelines, scale has to be considered. If you need to scale up the construct, then the treeline/skyline will be out of scale. to account for that, I may make a second version of each, with the scale doubled.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5