Do I understand the QoS limitations of Cat6500 Sup720 correctly?

The configuration guide says:

Layer 3 DSCP-based queue mapping is available only on WS-X6708-10GE, WS-X6716-10GE, WS-X6716-10T, and Supervisor Engine 720-10GE ports

Since several of the ports that need QoS terminate to WS-X6548-GE-TX linecards, do I assume correctly that my overall QoS policy cannot effectively use DSCP values at all?

Since all 6500 ingress traffic will be 802.1Q, I could ensure all VoIP traffic is at least marked COS5 and therefore gets priority queue on egress. But regardless, it seems like my overall campus QoS design is constrained to CoS/IPP and I can't leverage DSCP values that don't correspond to those.

Or have I missed something?

Edit Looks like I should mark DSCP values at the access edge, but then use dscp-to-cos maps on the 6500. This still limits me to 8 classes but I won't have to re-architect my whole design around CoS.