The best I can remember, the KL130 was middle of the road among brands for that size, the newer CKXX10 series loaders are now slightly stronger.
That being said I have done everything from grubbing stumps & sapplings (4" dia) to moving Virginia Red Clay dirt, asphalt millings, rocks, brush, logs, and a few smaller round hay bales and the biggest limiting factor I have run into was not the loader capacity but rather the lack of adequate counterweight to USE that capacity.
Even WITH filled rears, the KL130 requires a 700 lb counterweight (per the manual) and I just don't have anything that heavy duty. I did make a ballast barrel with steel & concrete but then I added a Quick Hitch and it won't fit my barrel geometry & I haven't reworked it to fit.
This is merely my opinion with no scientific basis whatsoever but - if you have work in mind that you think you'll need every last bit of loader capacity then I would step up to a larger tractor. You'll be happier with a machine that's working to 70-80% capacity than one that's maxed out, plus it will be better for the tractor over it's lifetime.