Carb throttle shaft o-ring

912ULS with 250 hours, just back from 70-hour tour of US. First-time carb inspection. Rotaxowner video addresses replacing the throttle shaft o-ring -- IF other o-rings show wear, which I don't expect since engine runs like the proverbial Swiss watch. Interested in info/feedback regarding removal and reinstallation of throttle shaft, especially the challenging-looking process of peening the new screws. How often have maintainers done this? Every 200 hrs? Never? Thanks!