Patch Available - KMST 1.2.456

As every equip sans special ones can now drop it basically means that you can either SoK or drop a level 140+ equip that would have been ideal for another character of yours if you got it on the wrong character because of this system, it would have been much better if they only started to require SoK/PsoK after you equip it like the current Cygnus equips.

That is how they are, untradeable upon equipping. You only need the SoKs after that.