I like the new rework system but i managed to work it so my factory to gets a fix every time by using smart junctions. I think it would be a good idea to make it so a car can only go thought each rework station once so gives you a bit move of an incentive to rework throughout the whole factory instead of just at the end like i have done.
Nice layout of the Rework slot.
I would still have a Visual inspection just after the Rework station as there is only a 80% chance of detection and fix. 90% with the upgrade.
I dont think this is too game breaking, as its quite possible you would end up with conveyor congestion if your defect rate is too bad anyway.