After looking all around DisplayFusion's settings I can only find 'Taskbar Opacity'. Which makes the entire Taskbar invisible, when the effect I'm looking for is opacity of the Taskbar Background, similar to StartIsBack. I've added a photo of both the Taskbars, StartIsBack and the Multi Monitor one.
This is currently on our feature request list, so I've added your vote to it. We'll be sure to let you know if/when we're able to implement it in the future.
