RE: Diamond Edge draw weight, should 50#= 50#?
It's not just the cables. If it were just the cables then the draw length would have gotten longer and they weight would go up. Most likely it's both the string and cables, in which case, there is less preload on the limbs. Check the A2A (probablky long) and the brace height (probably low).
You can twist the present string/cables to get the bow back to specs or as you already have experience with them----Bucknasty.