Those “AWD Lock” systems are all brake assisted not a true 4x4 locking system. Even the new Land Rovers use that system. Sure it works great for traction but it cuts max power.My brothers Toyota sequoia's AWD system works well, you can lock the center differential when you need to and run it with AWD low range too. With the center differential open you get a better turning radius.
So if you had the center diff open and as you turn the brake system locks up the inner rear wheel you would have a turning radius of around the length of the vehicle as you spin around the one rear wheel. That would be amazing. I know of some trails this would be useful on.