When I'm googling for a way to disable the Optimus technology, what I find is threads on forums where people make that exact same suggestion: Disable the Intel device driver so that it forces it to use the Nvidia device driver.

All those forum threads end the same way: It doesn't work. The most common result is that the Nvidia card won't work at all because it doesn't have the intel's framebuffer to write its images to, and/or the whole OS won't work with anything but basic low-rez low-color video because it doesn't have any drivers for the main display adapter.

And anyway, that's not the issue here. I'm not getting a situation where the OS is trying to switch to the Intel display. It's still using the Nvidia display, it's just throttled its voltage because it thinks I don't need it for some reason.