Wow - Torsten - Amazing suggestion!
In a way, you are manually recreating presets through individual control changes in Cantabile states. It might lead to some surprising results if you miss any given control for any state, however - this does effectively allow Cantabile to capture preset data in a state.
If you are pedantic about specifying all parameter details ( (raising my hand) sometimes I am! ) this is probably the way to go.
OK - one more question:
Is there something like a 'parameter editor' view for plugins in Cantabile, where one can view VST parameters and values for any given VST's current preset?
(This would make capturing parameter state much easier)