If you try to use this sample project from Nvidia:
github.com
You'll get a crash in graphics-hook64.dll when trying to create the swapchain for the monitor that isn't part of the main desktop.
GitHub - nvpro-samples/gl_render_vk_ddisplay: OpenGL sample that renders into a Vulkan direct display
OpenGL sample that renders into a Vulkan direct display - nvpro-samples/gl_render_vk_ddisplay