How to smooth the edges in tiling rotation?

Hi, I have followed a tutorial to set up a landscape texture that has tiling rotation to break up the patterning, but as you can see in the final screenshot of the texture in the world, you can see the hard edges of the rotation very clearly with the texture I am using. Does anyone know what I can do to feather the edges where the texture rotates so it’s a smooth blend/overlap rather than a hard edge? I have tried various search terms, but haven’t found anything.

Thanks for your help