I have found that if hovering the mouse cursor over the menu system at the top of the screen is is laggy and if running animation I only get 3.1 fps. This is when using a G-SYNC screen and if iClone is in the foreground. If bringing up another application over the top of iClone then iclone responds at normal speed i.e. 60fps and also there is no lag if moving mouse cursor over the menu options at top.
If you move iclone over to a non G-SYNC screen then there is no issues.