Extending the "feet" of wire shelves for uneven surfaces
Metro does not seem to sell an appropriate foot leveler.

But a common carriage bolt will fit just fine.  The rounded head compensates for the slope far better than the flat factory foot, and you can file the raised numbers off easily:



Or find a 3/8" 16 pitch "Combination Leg Equalizer" such as the Rockler #24315, which will spread the load more evenly: