I used the 1/4" version of that to restrict the flow back to the valve from the dump side of the curl cylinders. There's not a lot of of flow to the loader so the 3/8 is not needed (and would make adjustment more difficult). And I put two on the backhoe's boom to make it less jerky. You could apply that to other circuits. For the loader I found a setting that reduces but does not eliminate bucket flop while not slowing dump down too much.
The connections between the soft and hard lines on the arm of the BL25 loader are JIC-6 and that's where I put the valve. I can adjust it from the operators station by standing up and raising the loader.