Is it possible to "fork" a VM?

[stroiman]

For my headless browser, I create a lot of VMs. There's quite a lot of initialization of the VM, adding all the relevant prototypes with operations and attributes, objects, and functions to global scope. This process is repeated for every script context, which can be a lot.

Is it possible to create a "skeleton" VM configured with the initial global scope and fork it, so I only have to setup the global scope once?

[stroiman]

Just took a peek inside the code, which uses a "template" concept for the native JS global scope values, Object, Array, etc.

But it appears to be unexported functionality, so apparently only intended for the runtime itself. But it would be very useful for other use cases as well.

Could it make sense to have that exported?