how to get the edited automation curves from the automation lanes (lets say CC11 - Expression) back to the object automation, once extracted from there?
You will need a plugin that allows real VST MIDI out, by default this option is always shown, for any VSTi, but that does not mean that it works. I used for this test MIDIChFilter from CodeFN42 https://www.codefn42.com/midichfilter/index.html
In your track to be converted (source), plug in MIDIChFilter, in the plugin menu enable VST MIDI out (top, provided by our DAW)
Create a target track, MIDI, enable VST MIDI out - Recording. In the header of the mixer, or in the track header MI