OmniFocus Feature Request: Provide 1st-class support for items in a 'Waiting For' state

I just sent this request via email to OmniFocus support.  After I wrote it I searched around and found a relevant thread proposing a similar idea on the OF support forum.

 
As a user of OmniFocus, I want to be able to filter out projects that are currently waiting on an action from another person or occurrence of an external event.
 
Many OmniFocus users, including myself, create a context named 'Waiting For', but doing so is not particularly useful.  What I need is to be able to filter out projects that are in a 'wait state' from my current list of projects in order to have less noise and avoid being overwhelmed.
 
Today OmniFocus has 'Active', 'Stalled', 'Pending', and 'On Hold' project states.  I suggest adding a 'Waiting For'  project state and a project filter called 'Actionable' .  Actionable projects are technically 'Active' (they are not indefinitely 'On Hold', and I may not wish to set a future date in order to make them 'Pending').
 
 
Consider the following use case which assumes the feature has been implemented:
 
* I have my OmniFocus Project Filter set to 'Remaining'
 
* I have a project called 'Sell my house in Seattle'.  The current task in this project is to email my real estate agent and ask him to do a market assessment.
 
* I complete this task and check it off.  I create a second task entitled 'Waiting for agent to respond re: market assessment'.
 
* During the creation of this task, I indicate via a new control on the UI that this is an item in a 'Waiting For' state.
 
* Because this task is the next task to be completed for this project, the project state changes to 'waiting for'.  An appropriate overlay shows up on the project icon, just as happens when a project becomes 'Pending', 'On Hold' or otherwise transitions state.
 
* I switch my Project Filter to 'Actionable', and the 'Sell my house in Seattle' project disappears because it is in a 'Waiting For' state, and is thus not 'actionable' by me right now.
 
* OmniFocus is now significantly more useful to me, because I know that the projects in front of me are all things that I can actually work on immediately.