Octachisel

Carve any full block into eighths with the chisel, modded blocks included, then place and mix those eighths freely. Build vertical slabs, stairs, and anything else that fits a 2x2x2 grid, out of any block you can hold.

Shaders: chiselled blocks report the material they are made of, so block-ID driven shader effects such as Complementary's integrated PBR treat an octant of stone as stone rather than skipping it.

Create Aeronautics / Sable: chiselled blocks render correctly on assembled sub-levels.