Sorry, I don’t get it. 
The wavetable editor is literally identical to the LFO and envelope editors - it’s the exact same UI.
Why or how is it better/faster to copy/paste and move back and forth between the wavetable editor and the main UI?
What am I missing here? 
The difference is the ability to quickly “paint” in series of saws, squares, half-squares and slopes instead of connect-the-dots-ing them, I guess 
exactly what shading and lighting said, you can quickly paint in shapes and flip shapes in the lfo editor, as well as its just one less window to open, you can quickly readjust your wavetable and paste it on multiple oscillators, its mostly just a workflow hack
What would be even greater, if we could import these as frames in the wave table editor. At the moment it replaces the complete wavetable.
Agreed. that strikes me as the next big feature that needs to be adopted: a way to easily paste individual frame/moments into your complex wavetable.
i requested this in the beta feature request and it seemed like he was down to implement that
I requested this after I made that video and I think he plans to implement that in the future!