Can be a bit finicky trying to bind the back buttons. Sometimes it works, often does not. The two inner (k3 and k4) buttons require too much force to be comfortable and the click sound is much louder than expected. The outer paddles are a bit quieter.
Note:This same company offers a premium 4 back button option called the Phantom which they sell under their offshoot brand, Hex Gaming. It's pricier, but from a features standpoint, it's the king of PS5 controllers. Improves on all of the issues that I had with the this remap kit.