I am starting to store my entrance reducers under the telescope covers on
hives that have them.  The 3/4" stick raises the cover about 3/8 above the
inner cover.
I place them against the rim of the inner cover at the back and put the
telescope cover on top. I hear some guys that use queen excluders store them
under the lid also.
For what it is worth you get improved ventillation and no sunlight coming in.
Tom