Image Source: USPTO
As for the regular controller, Microsoft apparently obtained several interesting patents last month. One of the patents deals solely with improvements to the trigger feedback.
“A user-input device includes a user-actuatable trigger configured to pivot about a trigger axis, a rack gear interfacing with the user-actuatable trigger, a force-feedback motor including a drive gear interfacing with the rack gear, and a posture sensor configured to determine a posture of the user-actuatable trigger about the trigger axis. The force-feedback motor is configured to drive the rack gear based on a force-feedback signal,” MIcrosoft explains in its patent.
There’s another patent application that details an adjustable-tension trigger. Just as it sounds, this would enable developers to program different levels of resistance on the triggers, based on what’s taking place in the game. It’s all about increasing the level of immersion, just as rumble feedback is supposed to do.