Radial Voronoi Noise for procedural island?

Hi there, I am currently creating a procedural island generator, and I am able to generate hexagonal tiles (using them for the desired shape) and apply Voronoi noise to the vertices of each tile hence mapping them out in a mountainous format.

Each tile is a separate object.

This is halfway there, since I would like to smooth the terrain downwards at the edges of the mesh creating the island like effect.

Does anyone know of any methods to do this? It does not have to be another noise generation method, it could just be a method for flattening the edges while leaving the center tiles untouched.

Any help is greatly appreciated!

Here is a screenshot currently: