de facto,
I would love to know what type you fly, is it an An-224 with four engines turned off, or maybe a B-52
Are you honestly saying you need every single inch available for ASDA purposes on a 4000m runway?
Having just done a "fag packet" calculation, you'd lose more than 20m in distance if about 40 pax were overweight on the standard by 20 Kgs in an A320, but you would rather put stress on a piece of very highly stressed metal to save yourself 20m. The mind boggles.