First off, for the ShanWan PS3 joypad (a PlayStation 3 controller clone), they managed to disable the rumble motor that currently starts immediately after you plug the controller into the USB port of your Linux computer, as well as to hard-code the HID service that the joypad was supposed to offer but it didn’t because it’s not Bluetooth compliant.
Among other Bluetooth improvements, the developer reports that he managed to add support for the standardised method offered by Bluetooth LE (Low Energy) for devices to export battery status information in BlueZ, the official Linux Bluetooth stack, which can be implemented at desktop level through the UPower utility. This will add better support for some Bluetooth LE/4 joypads.