While there are reasons to let hammers down, taking the tension off a spring isn't really that important. A properly made spring has a finite number of flexes. The act of loading or unloading is the wear factor. The only V-spring I know of that broke was a 1899 grade 2 LC Smith. I watched as a WWI vet took out the Luger he bought home, and unloaded it. The mag had been fully loaded for at least 40 years maybe longer, and you still have to use the loading tool to fully load that magazine. If It makes you feel better dropping the hammers and letting the tension off the springs, go for it, but it will bring you one flex closer to failure. Hopefully that will be another 100 years from now.
