1. Doffy's strings disappear when he's unconsciousnope watch the fight again he always said luffy's attacks in G2 were fast. and he says im not fully healed and im replacing it, if he didnt he would die at some point. its a decent fix and thus he could still fight and use all his top moves, hes implying its not a complete fix but it does the job and its further proved by him not dying. not a plot hole ur just denying the manga at this point. he is in no way nearly dead in his whole fight with luffy.
2. His strings are the only thing keeping his organs together
3. Doffy said his stitching is NOT healing his organs
So please, by all means, explain how Doffy's organs stayed together and didn't fall back apart after he was KOd, other than plothole.