For this to works, one of the similar equipment must be LOWER in level. Haven’t tested for thrown/wands and for items with same level. So if one of LOWER leveled equipment are CURSED and EQUIPPED (can’t be unequipped), for some reason it will not be destroyed by reforging process.
First case I encountered was with Displace Plate +2 (equipped) and Anti-Magic Plate +3. Reforging result was Anti-Magic Plate +4 but somehow the cursed Plate +2 were still intact and equipped. Then I tried again with Curse Infused RoW +0 (equipped) and RoW +9. I was able to get RoW +11 by reforging twice using the same cursed RoW + 0, and it was still intact after the second reforge! Proof for the second case below via imgur.
Kind word, thanks! Tho it’s more of an accidental discovery. Cursed item can be processed by the blacksmith only since the new reward system from v2.2.x. Before that the items do have to be uncursed.