2020 Colorado Z71 Trail Runner
They do need to be rebuilt, I don't know how often. Most aftermarket shocks need to be re-built every so often. My Fox's say every 50k miles or so. The only aftermarket shocks that do not need to re-built, that I am aware of, are Bilstein and OME. And maybe Eibach.You should drive it! Then you can report back so we can all spend more $$.
Being serious, I thought I had read somewhere that the Kings require more frequent rebuilds. True? Or was that Icon's?