I don't know if this has been pointed out before. I was RE'ing implants last night, specifically the Overkill Nano-optic Resolve implant. I have already discovered the Rampart T-2 prefix however, being a Sorcerer that's less than ideal so I have continued RE'ing the Overkill in hopes of getting something more useful like the Expert T-2 prefix. Apparently it is possible to discover a schematic that you already know giving the message "You have already learned that schematic". I don't know if it's a bug or intended but if it is intended, that's a pretty harsh mechanic on something that takes RE'ing 40+ blues to discover.