Cisco Firewall :: Possible Limitation Of ASA 5505 DSCP Markings

following about a limitation on the ASA5505.I have a client that has a number of branch offices on a Gen-I OneOffice network. For complex and political reasons, we can’t trust all nodes on that OneOffice network. We need to put a firewall at each branch office between their local network and the OneOffice router.
 
To avoid having to either readdress the OneOffice routers (politically difficult) or readdress each branch office (logistically difficult) we’ve suggested using a transparent mode ASA5505 firewall between each sites OneOffice router LAN switch.
 
Recently I’ve discovered the client is deploying Avaya VOIP phones into the offices using QOS/DSCP over the OneOffice network from Avaya units in some offices. I figured I’d need to trust DSCP on the way though the ASA and went about looking at how to achieve that.
 
I found the following document relating to configuring QOS on the ASA: url...
 
This suggests in the DSCP and Diffserv Preservation section that “DSCP markings are preserved on all traffic passing through the ASA.” However, in the Guidelines and Limitations section it suggests QOS isn’t supported in transparent mode.I’m a bit worried that the DSCP markings won’t pass through the ASA5505 in transparent mode.