I just went into ACDAPP to look at my switch config for the ACD agents, and I don't have autowork configured for any of them. Normally the switch programming only takes over if no heartbeat is seen from the OSCC, but there are some strange circumstances I have had to allow for where that is not completely true - like in the "backup routing" on the 4000 I had to put a 5 second delay in AFTER the first "If Heartbeat then Route to OSCC" statement in each backup ART to give the switch time to actually give control to OSCC before it continues on down the ART as if there is a failure. The very well educated tech I work with says if the first announcement or music or whatever comes immediately after the switch could transfer the call to the recorder port before OSCC tries to grab the call and it can cause calls to be dropped during peak times.
In the OSCC though, all of my agents have autowork enabled - I usually use 15 seconds and figure if they need more than that it gives them time to hit unavailable before the next call arrives.