Believe me, I sympathize with the monotony of dispelling the same myths and tropes regularly. It's why I usually reference prior comments of mine before making a bespoke comment or post, and tweak to better suit the context, similar to what you do. I'm a firm believer that simply explaining and refusing to take cheap rhetorical wins results in long-term ideological cohesion in internet communities, raising the general average understanding of those who use these forums, and results in reduced work load in the long run by increasing the number of people that can actually respond well.