growth.blend (1.3 MB)
Volumetric mesh growth with Simulation Nodes in 4.2a. Pretty simple node setup. I’ve discovered that new Bake node works better than baking the Simulation Nodes in Physics tab (it takes less memory and hdd space).
Blend file attached, you can try playing with different settings
Wow! This looks really cool! Thank you for sharing the GeoNodes setup, such a relatively simply approach is probably tweakable to all sorts of things. 
It looks like a marine sponge - so cool!
Wow, real cool!
This look great. I wonder if with another material this could look like a pyroclastic flow or smoke rising up from an explosion or volcano.
I featured you on BlenderNation, have a great weekend!
