I only missclick the quests rarely so I’m not sure how many are affected. But if that’s the case for all such quests, I think it would be best to just take away the accept option if the “already gone and did it” option is there, similar to what happens with, say, the Iris of the Eternal Night quest with Riggs. If you have it there is nothing else to click other than “I’m literally holding it in front of you, dummy, take it off me” (paraphrasing, I think).