"Multiple monitor support" means that 2 or more monitors can be controlled separately, e.g. display independent screen contents.
Since Dexpot 1.6, all components of Dexpot are compatible with multiple monitors. In case you want windows on individual monitors to remain visible on all desktops and content to be static, you can exclude monitors from desktop switching via 'Settings > Switching Desktops > Monitors'.
However, it's not possible to display different virtual desktops per monitor.
Here's a list of cool applications for monitor-specific window assignments and separate taskbars: