I often work with the equalizer. It would often be helpful to be able to undo the last setting or the setting before last. Otherwise I always have to remember them. Is there a possibility such as CTRL-Z?
No. Ardour does not have any mixer undo/redo functionality.
In Plugins i can save presets. Is this a stupid idea if you implement a left arrow (undo) and a right arrow (redo) next to it? But you should only be able to use the undo/redo function with a mouse click and not with CTRL-Z, because it is too dangerous.