And that block is screwed tight and solid to the bottom of the bridge saddles. So what ever vibrations happen on the bridge get sustain from the brass. “Mass equals sustain”. It’s not the tone though. It how long the note lasts. If you make a bell out of lead it doesn’t matter how you mount it or strike it it won’t sound. But brass? That’s a whole different monkey. Brass is resonant and the resonant frequency is malable by mass and shape. I bet the resonant frequency of the strat mass bar is smack dab in the middle of the lowest note and the highest note it plays. I don’t know that, but Leo was pretty friggin smart and if I can think of that he should be able to leave me in the dust. I think they put the most economical bar in that would adequately do the job to keep purchase costs down. I bet if you get a custom guitar from Scott Baxter that he doesn’t put on lesser parts to keep the cost down. He puts on it Whats perfect and correct so the final outcome doesn’t have thoughts like, “My notes don’t last very long, should I change the nut or the bridge saddle?” You can bet you have the best nut and bridge saddle there is and they are cut perfect. Unlike a mass produced item like a Stratocaster or Telecaster. On my Tele the first thing I did was change the bridge saddles because it would not intonate correctly it needed compensated saddles, and even though the tuners where vintage “style” they where crappy so they got changed too. That’s why there is so much mod parts out there. Is to improve what the factory skimped on.