Jose,
if you use the spanner wrench on the Paso shock you also move the hydraulic spring preload system. This might only be reasonable if you need an even harder or softer ride than can be adjusted by the hydraulic system.
Don`t know about the Paso shock but I`ve read in a brochure once that some shocks are set to a driver of 90kg weight by standard. In my case this would be too much and probably also hydraulic spring preload setting 0 would be too much/hard. In this case I`d need to use the spanner to decompress the spring.(compressing it will make it harder)
But honestly I`ve never done much adjustments with my shock, so I´ll leave this topic to the guys who really know what they are talking about
G.