For those who get issues with input lag on their bluetooth devices, do the following to remove the lag.
- Open up Terminal.app (Applications > Utilities > Terminal)
- Run the command
sudo pkill bluetoothd
(just copy and paste that into Terminal). - Hit Return/Enter.
- Enter your macOS user password (the one you sign in to your Mac with).
- Hit Return/Enter.
- Wait for a few moments while the Bluetooth receiver resets and all the devices restart.