I have tested this out once again 2 months after my last post about this issue and I was happy to see this patch note ages ago. - Fixed a bug where items would falsely state that they were providing a speed benefit (did not do anything). They should not generate anymore going forward
However I just made a speed set that gives "SpeedMultiplier: x18.0%"
Now I thought this would be +18% speed added on but testing against someone in same armor but basic version with almost no weight and both with equilibrium + max armor articulation he managed to be faster than me. Now this makes no sense and the only thing I can think of that would cause this is that it is x18% of whatever you have levelled into the stat. Now as you cant level speed this makes this stat completely useless. I propose you just remove this stat and convert it into the +SpeedMultiplier stat as that will just add it on as a percentage and make it work or just remove it altogether as it is very misleading.