Cisco certainly blocks the traffic when you apply the ACL to an SVI. Not saying whether it logically gets dropped on on the SVI vs the physical interface, but either way the traffic gets dropped.
Case and point, I have a pair of 6509's with the 2T supervisor, and there are a couple of SVIs with ACLS, and they clearly block the traffic from passing before routing occurs.
Now, if you are saying the that I have two access-port interfaces in a VLAN, and that VLAN has an SVI that traffic does not get blocked from physical-interface to physical-interface within the same VLAN that is true. That said, it does get dropped when the SVI comes into play for layer-3 functionality like traffic leaving its layer-2 subnet and a routing table being consulted to get it to some other destination subnet.
Are you saying if you put an ACL on an ICX VRI (i.e. a VE), that it will also filter the traffic between multiple physical interfaces within that same VLAN if routing doesn't occur?
Just asking because usually the Cisco Software Virtual Interfaces (SVIs) and the ICX Virtual Router Interfaces (VRIs) serve predominantly as default-gateways to get off a local subnet within a given VLAN, so there is usually Layer-3 routing involved regardless of the platform.