Generating Terrains at Runtime

I've been using Real World Terrain for a few years now and it's hands down my favorite terrain generator.

My question is about getting some direction on using this tool at runtime to generate my terrains.

What I want to do is give the user the opportunity to select a very limited area on the map, constrained to a square, possibly based on simply by providing a single lat/lon and center the square on that.  My thought was to try and see if if I could figure out how to get your terrain helper tool to run at runtime and use that to get the coordinates, but I might just see if I can just offer the user the opportunity to provide the lat/lon directly, where they get it from another place first.

Once the terrain coords are in place, generate the terrain like usual.  I'm not concerned with the time to generate the terrain at runtime, its expected and assumed.

I guess as the developer, I wanted to reach out to you and get your thoughts on how to best approach this task.

Thanks in advance