I always got the impression that our JD and Kubota both have rather conservative relief settings on the loaders. Mess with that, and you could start breaking things. Sure, you can lift more, but now you are carrying that extra weight. That load bounces when travelling, or you hit a rut. Counterweight is great, but there is still a lot of weight rocking back and forth, while in motion.
Need more lift. Buy a bigger machine.
Actually, that machine in my picture will lift 8000 pounds, and we only got it because the previous owner would drive through a rutted yard well loaded and a wheel broke completely off! Spicer axles, not exactly junk.