I use SLX and have encountered the twig problems that you describe with no damage.. also similar branch, bough, log, tree, copse woodland and forest problems.. with associated attacks from dogs, rabbits, goats, sheep, horses, hamsters, ants, cows and bison.. buffalo, anteaters, and several medium sized dinosaurs..
Mud, snow, sleet, hail, ice, grit, sand, salt and vinegar.. gravel.. pebbles.. rocks.. boulders.. avalanches.. rockslides.. meteor strikes.. nuclear war and very poor maintenance have all failed to cause the SLX mech any trouble at all..
I kind of fancy the Shimano Saint M810 mech (which should work with a regular hanger) when this SLX finally gives up though cos they look cute..