Glad to see this coming with gVisor support to help secure the Kernel- IMHO we should expect frontier models to find Kernel exploits.
I am working on a project similar in spirit that uses microsandbox (libkrun) to run inside a tiny and fast VM. It includes other security properties that are needed for some workloads.
* network allow lists
* credential masking
* github allow list
https://github.com/gregwebs/agent-vm/#agent-vm
Couldn't you use fine grained github tokens for some of what you're accomplishing with the github/network filtering?