I submitted a support request shortly before posting this. That request is 40600, but I have a small amount of additional testing info at the end of this post that was not included in that request.

Setup is this (Windows 10):

Monitor 1: Displaylink
Monitor 2: Displaylink
Monitor 3 (wacom): USB

Goal is to have 2 monitor profiles like below:

Main = desktop extended from 1 to 2. 3 is disabled.
Main + signature tablet = desktop extended from 1 to 2. 3 is enabled and mirrored from 2.

Main profile works fine.

Main + signature tablet profile works, but only after going into Windows display settings and changing the setting manually for 3 to "duplicate desktop on 2 and 3".

This would be fine if it was a one-time configuration, but when I toggle the monitor profile back to Main, then try to toggle back to Main + signature tablet, it fails and I get the below error:

"An error has occurred while applying your new Monitor configuration.
Please check your settings and try again.
Error: Failed to call SetDisplayConfig. [HR: 87]"

It seems like DisplayFusion may not be capable of enabling monitor 3 when it has been disabled. Possibly related to it being connected via USB? I hooked up a third standard monitor via VGA and toggling between the profiles works flawlessly. Any workaround for this that I'm missing, or could this functionality possibly be included in a future release?

Some more info...

It appears this problem may be some sort of combination of using a USB connected monitor and also trying to mirror it from another monitor rather than extending the desktop to it.

I created a profile (Main + signature tablet extended) that simply extends the desktop from 1-3 rather than mirroring 2 to 3 and that also works on the USB wacom.

I am having the same issue. The Wacom tablet mirrored fine with Windows 7 and DisplayFusion, but when you try to mirror on Windows 10 with DisplayFusion, it doesn't work anymore.

You can mirror to the Wacom in Windows management and it works. DisplayFusion even shows the correct mirrored settings, but as soon as you change anything in DisplayFusion, the Wacom mirror option in DisplayFusion disappears.

This will not work for us because we use hotkeys in DisplayFusion to switch between two modes. As soon as you press the hotkey to switch, it breaks the usb tablets.