Managed to fuse @runevision's erosion shader (sampled on a sphere) and @lisyarus's SWE Virtual Pipes fluid sim. It all works on a Yin-Yang chimera grid.

The fluid sim runs on two 1x3 storage textures (in this case 1024x3072) which are then mapped on the 6 faces of a texture_cube<f32>.

The exchange shaders between the Yin-Yang scalar and vector (MAC) grids works with simple bilinear interpolation.