I think the nostelgia factor has a lot to do with it....
If you look at the Photos, Postcards and Feldpost.... maybe up to the very end there seems to still be a romantic view of the war.... then all the way into the 1930s, a nostelgic view....
I am sure jewellers in the 1920s and 30s were also engraving crosses that friends and family were handing out.... for a guy in uniform, an EK1 was like a Tiara or Necklace for a woman in an evening gown... Who would not have appretiated a nice domed, engraved cross from an od Comrade on his 35th Birthday....
WW2 came to an end... and noone was engraving crosses after 1945....
Also... Silver is a nice engraved gift.... a valuable gift.... WW" crosses were cheaper and utilitarian....