To Temporarily Hide the Tool Settings Window

Make sure the PopSet icon in the Primary Tools toolbox is green, indicating this capability is enabled. If the icon is red with a diagonal black line across it, click the icon to switch the setting to the default.
Move the pointer to a location just outside the Tool Settings window.
The window disappears. To cause it to reappear, move the pointer further away from the window's hidden location.

Note: You can customize this capability by adjusting settings in the PopSet Properties dialog. For example, by adjusting the Hide Border setting you can change the size of the Tool Settings window border in which the presence of the pointer causes the window to disappear.