I have and I haven't been delivering code/tasks 50% faster when my monitor count increased by 50% from 2 to 3. Then went back to one monitor with virtual workspaces as that made me more productive than having to constantly move my neck eyes across a sprawl of windows. Plus having to manage windows around and tile them "just right" across several monitors always interrupted my flow, and worse, was costing me even more time when those windows were moving around and they weren't in the place where I remember I left them last time.
>Imagine [...]
But I'm not asking what you imagine it might do. I'm asking if it actually measurably improves your productivity, not if you imagine it could, because those are two very different things.
I also imagined that having as many monitors as an operator from The Matrix would make me more productive but it hasn't. My coding and task delivery speed has stayed the same or even gone down inversely proportional to the number of monitors.