Hi @waterproof,
To mirror flip the spacedesk screen for teleprompter use, you have to switch ON the Videowall mode via spacedesk Driver Console -> VIDEOWALL, then click the connected client underneath Unassigned (or Video Wall# if its assigned to a videowall).
On the right side panel underneath videowall client settings, you will find below the “Flipped Display (for mirroring)” checkbox and just check it.
For assistance, please check the attached image below.