Yes, it is done by some, in some cases. It helps lower the risks. But, in reality, you can mess up a cam lobe in many ways. My philosophy: if it is a low lift cam, and the spring pressure at max lift stays under 300 lbs, then I personally would not bother. But that is my personal view; YMMV.
Use a moly loaded cam lube and that will help reduce risks too.
There are plenty of lever type spring compressors to do this while the heads are on the engine. Do searches here and you can find some homemade ones.
What springs are you looking at?
