I've felt that not focusing on the fact that people may have bad faith and we need tactics etc freed a lot of time and energy to invest somewhere more useful
If you're talking to people who, for w/e reason, have large influence on your life, who you are stuck with and who are not very numerous, investing heavily in enforcing communications standards should pay off. Similarly in cooperative setting with aligned incentives you would expect assuming good faith to work out well.
Now, in social media, sales or a large fluid organization...
It starts with not assuming bad faith from the other side.
Trying to adapt your communication strategy depending on the profile of the other side is not really "good faith". The goal is to train _ourselves_ to look at reality in a less biased, personal way. Wanting to max out every opportunities precisely tends to distort reality.
Opposite experience. It leads to wasting time, especially compared to getting to the same conclusions using more effective, if less 'true', tactics. It just doesn't scale.
At some level good faith is superior on a very large scale, since the reality tends to provide a somewhat consistent feedback, but there remains a local niche of maxxing out persuasion skill tree. Not to beat dead horse, but large organizations with too much resources seem particularly prone - it is an obviously self correcting mechanism, but the tactic remains valid locally.