I would call Cary and ask what the signal path is.
On my Cary SLP-05 2 channel preamp the Cinema Bypass just shuts a relay that bypasses everything. You can even turn off the preamp and the signal goes through. The only residual effect is whatever you get from the input and output connectors and the closed relay, which should be pretty small. My guess is the 11a does a similar thing, but Cary can tell you. When I asked them about the SLP-05 the tech looked up the schematic to check. Once you know the signal path, you can decide if you can hear a difference with it in or out.
On my Cary SLP-05 2 channel preamp the Cinema Bypass just shuts a relay that bypasses everything. You can even turn off the preamp and the signal goes through. The only residual effect is whatever you get from the input and output connectors and the closed relay, which should be pretty small. My guess is the 11a does a similar thing, but Cary can tell you. When I asked them about the SLP-05 the tech looked up the schematic to check. Once you know the signal path, you can decide if you can hear a difference with it in or out.