I’ve slowly been adding Pro Tools and Reaper.FM into the list of softwares I know inside and out and one of the major things that those two DAWs do incredibly well is routing.
I would LOVE for Cubase to adopt one particular design element of PT and that is showing my routing information on the track lane instead of just in the inspector. I do a lot of routing decisions on the fly and having them all accessible so easily like they are in PT would be wonderful.
Additionally, another great design feature for routing comes out of Cockos Reaper, where you can literally drag the I/O region (or in the case of Cubase, the Sends button, perhaps?) onto another track - or even another plugin! - and instantly either send audio to that track, or side chain audio to that plugin. Makes routing a breeze and it would be excellent to have those sorts of workflow improvements to Cubase, in my opinion.