Under Map Properties, Map Options, select Floor plan in "Display objects as" drop down. Add devices to the map.
From what I can tell the devices will now be rectangles only, which can be resized by clicking and dragging the bottom right corner (and only the bottom right corner) of said rectangle.
From what I can tell the devices will now be rectangles only, which can be resized by clicking and dragging the bottom right corner (and only the bottom right corner) of said rectangle.

