My apologies for not using the correct terms or concepts. My basic goal is to provide functionality that would enable timeouts for runspaces in a runspacepool.
I tried to add a timeout to Tome T.'s Foreach-Parallel function but was unsuccessful - defining a 'start time' when a runspace is defined is inaccurate, as the actual runspace is queued up and may not start when this property is defined. Details here: http://gallery.technet.microsoft.com/Foreach-Parallel-Parallel-a8f3d22b
Boe Prox suggested using nested runspaces. This allows for accurate timeouts unlike the above method, but severely impacts performance, the main motivation for using runspacepools in the first place.