I see that I can dock the viewer to any of the four corners (Top, Bottom, Left, Right) of the IMatch screen, while it's in Panel Mode. In this state, is it also possible to float the viewer, as can be done for all the other panels?
Use the Window mode for the Viewer to make it freely movable. See Viewer Modes (https://www.photools.com/help/imatch/#viewer.htm?dl=h-6)