It's COW with fork. So if your child calls into the API, it will impact the parent's API session.
You want to be sure you clear the VIM global. You might want to initialize a new VIM session using the same session id from the parent in the child. So two sockets. Just be sure one doesn't disconnect before you're done with it. You can change the behavior on VIM going out of scope (undef) with "unset_logout_on_disconnect()" on the VIM object so it will not close the session if a child or parent is destroyed. Then be sure you call logout on your own.