Very cool project, and great for many usecases. In absolute performance, I find it about 16x slower than CPU [1], but it'd still be super fast compared to the full Linux GUIs we were using comfortably in the 90s/2000s on slower CPUs. Might work for sandboxing user code as well.
[1]: My utterly naive benchmark completes in 9s - time seq 1 50000000 | wc -l