Since I have been busy doing LOT of setups today for the first time, this is my prefered way ATM.
First I set up all my cards to get the final output for every single camera. In the course of the project these setups will be updated as needed.
If I want to do something more “simple” with a certain camera setup, like doing test renders without output, I just create an empty setup and only enable the render output-common card with an empty path (so nothing is saved) and also enable the render settings-preset card with a fast render preset. You now can select any final setup and then click the test setup for test rendering. The point is that empty setups only overwrite complex setups with the cards you have enabled, so if the camera card is disabled you can use these cards on any camera specific setup.
If there is a faster or better way, I would really like to hear any ideas.