the DGL is for locking both front wheels to turn at the same time in 4x4 mode . the front wheels are still controlled by the switch and the bike will still switch to 2x4 mode and turn normal with a DGL locker installed.
most all new hondas only have one front wheel with power to it at a time so the bike is not a true 4x4 but a 3x4 and the DGL fixes that .
Now a spool locker is cheaper and it does the same thing but in 4x4 mode the bike will be harder to turn because there is zero slip between the front wheels when turning, they turn at the same ratio. which causes one to drag .
kinda like its shorter to take the inside line in a race , the outside is longer and must turn more .get it?