zaw's[1] history widget on Ctrl-R is so much better than the regular backward history search that it's difficult to imagine using a shell without it anymore.
I've also been working on tools to make user context switching easier on the terminal (such as a project of mine called prm[0]), and I'm currently working on bringing this sort of functionality to the desktop environment.
If you (or anyone else) wants to talk about these sorts of things, or know of any good relevant research, please drop me a line here or at eivind dot arvesen at gmail dot com.
On the surface, Desk workspaces seem very similar to tmux sessions. I'm curious why one would choose Desk over tmux to manage multiple workspaces in the shell? https://robots.thoughtbot.com/a-tmux-crash-course
No it would not. I cannot begin to count the hours I've lost debugging ruby script based tools implicitly dependent on this behaviour. Just no. rbenv is better, particularly due to totally not doing that sort of "magic".
1: https://github.com/zsh-users/zaw