When applying Travertine Blocks to a T6 Storage Silo, I noticed that the required skill level was 1000 and the optimal 1325. With the Travertine Keys the required skill level was 1100 and the optimal 1425. Requirements are the same for the other materials as well. After checking other sources the optimal requirements were lower (Blocks 1200 - Keys 1300) There is definitely a difference and am wondering which is correct and if the optimal requirements should not be lower. Is anyone else having this problem?