To my knowledge, this is the first time anyone has done this in Godot
There is Zylann's godot_sdf_blender. Not sure how it compares, though.
octree based
It would be cool to have Cube 2: Sauerbraten map support (I especially like things like arches and other mesh details). Though a lot of the look can be done with meshes+vertex colors (more materials for things like glow, metal) the missing piece for me is the map editing workflow* particularly something more intended for modularity (Godot's gridmap is clunky when it comes to multiple cell sizes).
* I haven't been able to try the new vertex snapping, nor Trenchbroom/Cyclops
I wonder what that and this could do together.
Excavation game? Both in terms of globbing dirt to walls, and dynamically dividing walls down that convert to SDF objects when small enough for digged surface. Actually this seems to exist as well, JorisAR's GDVoxelTerrain:
This project adds a smooth voxel terrain system to godot. More precisely, it uses an octree to store an SDF, which is then meshed using a custom version of surface nets. Level of detail systems are in place for large viewing distances.