This editing technique is still used in Classical Music as it’s way faster if you have several long takes.
The basic features are already there! The fade editor is just fine for that purpose.
It’s also already possible to split the arrange-window to have two independent timelines.
The only thing left is a function to copy between them with one button.
It’s would be possible to create a macro, but as far as i know there is no key command to switch between the two arrange windows…
Benefit for Steinberg: There is no other DAW on mac that is capable of doing 4 point editing