[dwattttt]

I don't think it's an elegant design at all; I think it's a workable design given the constraint of requiring fork.

It's an achievable result with less specialised parts, but there's a reason we don't write all of our logic in NAND gates.

I'm still only inferring what you meant by CreateProcess needing special facilities; I assume you meant opt-in fd inheritance. Saving a parameter call while forcing all fds to be shared/duplicated seems penny-wise but pound-foolish.