The ancient and much–repaired Sears humidifier works better in its new location across the living room with its front raised a few millimeters, which may have something to do with its plastic housing supporting a pair of heavy water containers for a few decades.
After fiddling around with shims to find the proper height, these feet descended from the Husky workbench feet:

They’re glued up from 3 mm plywood sitting on a 1 mm layer of cork:

The humidifier seems much happier with its casters 4 mm above the floor. Seems awfully fussy to me, but there’s no arguing with success.
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