As someone who has been getting into CAD lately and has several years of experience working on 3D models in Blender, I would very much prefer to be able to walk around the model and make adjustments here and there rather than using keyboard shortcuts and the mouse. More display space in VR should have an emphasis on "space" rather than "display".
If we're talking about programming instead, an intuitive way to switch between modules when working on a large project would be to have their windows laid out before you on a virtual desk and you could switch between the active one displayed on a central virtual monitor by making a gesture (probably something like the Oculus pinch) towards the window you want to switch to. This would allow you to use your spatial reasoning to remember which windows you have open and would also allow you to group related windows. Additional displays could show console output from your development server, the GUI part of the app you're working on, a test runner, etc. positioned where you can glance at them easily.
That being said, I think the real killer app for the new "facetop" computing devices that are around the corner will be physical fitness and social interaction. If you think a standing desk was a big improvement for your health then you'll love being able to freely walk around your office and work from any position whether it's standing, sitting at a desk, perched by the window, lounging on the sofa, or even crouching while giving those legs a stretch. You can also kiss zoom meetings goodbye with the unnatural wall of faces almost but not quite making eye contact with you. You'll talk to an avatar, realistic or not, that has full eye, face and body tracking allowing you to tell if your interlocutor is paying attention or thinking about how long it is until lunch while checking the wait time at the nearest restaurants. It actually does feel like you're in the presence of another person and spending a few hours talking to people virtually will no longer leave you with a headache and eye-strain.
I'd also invest in learning how to use a one handed, portable chording keyboard, it'll probably be useful.