I`m no expert either I thought that way of free cam spinning is when you change closer shims and are figuring out the right size of shim. I mean when you have opener rocker moved out the way. Like in this video;I am no expert, but I believe that when the closers are tight it can cause the cams not to spin freely. Also, when I was doing my ST4, I didnt get the collets back seated correctly and it caused a cam bind. What were your closer measurements? Did you make adjustments?
I don`t feel any "drag" when spinning. It`s more like it takes more force to get over the point, where valve is fully opened.
I did change opener shims, but not any closers (yet). Measurements on exhaust closers were very tight on both, <0.03mm/.0012" It`s impossible to measure so small gap :/ When pushing down closer rocker arm and spinning the shim, horizontal wheels maybe a little tighter.