So you think that's the legacy UI? I don't get why it's so far removed from PC, it's even further away than what we have now. I think DR might just be building on their existing mobile version to save some time.
Legacy would be much akin to what you have on Console now - which is fairly close to what we have on PC. Obviously, it would need to weave in the 1.4-era additions (Journey stuff, etc). That has not been finalized yet.
It's good that we'll be able to use a keyboard to navigate the dupe menu though, typing on a controller is a ball-ache. Wil we be able to have both running at once, so that we can play with a controller but browse the UI using a keyboard?
Great question - I really do not know. Will check it out next time I'm testing a build.
The overall idea here is for a consistent experience - but one that is tweaked as it is needed to take advantage and optimize for each platform. The vast majority of those tweaks will fall under UI and/or controls pretty much. As noted in the big red text above, all of that is still WIP.