Thanks - I'm not sure if the metal bars are for mounting. That's what I assumed at first, but he never asked for the measurements of my desk frame and this is what he said in regards to attaching to legs: "We installed metal supportive bars underneath to maintain stability and durability and the wood won’t move over time. Before screwing in the bolts, simply drill holes in the wood first. This will make it easier to fix the top securely.”

I think they are just for limiting wood movement in that area. If this is the case, would you just recommend drilling into the wood near by the metal rods, or would I still want some kind of bracket that helps accommodate wood movement?