Hey there.
It doesn’t appear (to me, anyway!) that the erosion function is multithreaded. Is it? If not, I’ll throw this into the suggested features section. The calcs take too long when you factor in geo time enhancement. 
Cheers,
Eoin.
Erosion is multithreaded.
Have you set the number of worker threads to something >1?
Sorry - it is too
On 4096 terrains the number of active threads is 1 for so long, and eventually switches to 4