Controller tracking coverage undergoes a significant transformation in Quest 3. - Road to VR
Quest 3 Brings a Big Change to Controller Tracking Coverage
Meta Quest 3 will introduce new controllers called "Touch Plus" that do not have a tracking ring. The IR LEDs from the tracking ring have been moved to the faceplate of the controller, and a single IR LED has been added to the bottom of the handle. This change in camera placements means that the controller tracking volume on Quest 3 will be different from Quest 2. While Quest 3's cameras do not capture above the user's head as well as Quest 2, there is more tracking coverage around the user's torso and shoulders. The haptic feedback on the Touch Plus controller is improved but not on the level of the Touch Pro controller. Touch Plus also features a two-stage index trigger. However, Touch Plus does not include some niche features of the Touch Pro controller, such as the pinch sensor and pressure-sensitive stylus nub. For more details, visit the source at Road to VRMeta.
Source: https://www.roadtovr.com/quest-3-touch-plus-tracking-coverage/