This is a improved prototype system that allows for terrain data to be exchanged for other terrain data using interpolation. It is quite slow, but works as a proof of concept.
As requested, I have linked the project for download (updated version) :
https://bit.ly/TerrainProjectDownload__
Here's the script by itself that makes it work (updated version):
https://bit.ly/TerrainLerpScript_
If you end up using it for something, I'd love to hear about it!