Idle timeout for copy/colon mode?

1) start up a screen
2) run top in it
3) Enter ^A: -or- ^A[ (colon or copy command)
4) Display is frozen

Eventually top or whatever other process you have running in the  
screen will get stuck trying to write output when screen's buffer  
fills up because display updates are locked while colon or copy mode  
is active.

Is there a way to set an idle timeout so that after a specified  
timeout (for example 300 seconds) of no input from the user, any  
active copy or colon command is automatically aborted?

There doesn't seem to be an "autoabort 300" command available.

I see the idle command allows a command to be run after an idle  
timeout.  And it does trigger when colon or copy is active, but there  
doesn't seem to be a suitable command to have it execute that will  
abort any active colon/copy command while being a no-op if neither  
command is active.  Or maybe I was just unsuccessful in finding it...

Any ideas?

-Kyle