I can't use 36 or 22t chainrings. I use a road triple crank and the chainrings I have are the smallest I can fit.
Front derailleur failures are indeed rare. I'm not sure why I've had two fail in the past four years. As far as I know there is nothing unusual about my shifting habits. Given that the same model of derailleur failed at the same place, I assume it is a design weakness. None of my other front derailleurs on my other bikes have ever failed.
That does seem odd. I shift constantly (hilly terrain and preference for resistance) and have yet to kill a front derailleur. I've replaced every other component on two bikes, but not a front derailleur. Wish I could help with your search, but I've got no useful information there, I'd say you are on the right track with looking to try a different model though.