OptiSurface Designer can run on multiple monitor set up.
If you drag OptiSurface Designer with a loaded file from one monitor to another, the application map may freeze and hang up.
Open OptiSurface Designer on one screen without loading any files or designs yet. Drag the software window to the desired monitor then load the file. If the problem persists, then you need to use OptiSurface Designer on the main screen because there's a limitation with your graphics hardware.