You can use the frame itself as an anchor to bend the center strut. Just leave the canti posts un mounted, but the center done up tight and pull up. I’ve done it, worked well.
Also you can mount a fork mounted cable stop behind the rack to get a good straddle cable angle and decreased shutter.
What’s the biggest jockey wheel you can stick in a Campy 11 speed derailleur? Need some new pulleys for my record derailleur, and a friend offered me some 12t KCNCs.
Left side drive however, so perhaps it is inadvertently fixed?