How to elevate the height of the landscape without damaging the quality?

Hi, my team and I work on a big project, and we decided to make a very big landscape to make a island.
So I begin to build the landscape with the World Composition tool to dissect the map without damaging the quality and everything work.

But there is a problem, the maximum height is limited and I can’t make big mountains, so I tried to make it highter by increasing the Z value on the details of the landspace but it significantly reduces the quality of the land and we can see the polygons when the mountains are created.

So I wanted to know if anyone knows how to increase the maximum height properties without losing quality.

Sorry I can’t answer, but I’m facing a quite similar problem, have you found a solution for it?