Hi Derek,
I like your name, since it is the same as my first Great Grand son's, born recently.
Don't know the answer to your question, but I do remember when shopping for my L4610, the specs said it had a heavier front axle, steering, hydraulic pump, as this machine had been optimized for fel. I don't believe my tractor could handle much more lift capacity without really heavy counterbalance.
I am like you, always need just a little more than I have, but am still amazed at what these little machines will do.
Attached is picture of concrete I pulled out of the ground with my 782 loader today. Had a bush hog 286 mower on the back. (982 lbs x 114" long). Even with this on the back it was difficult to keep the rear wheels on the ground just moving it to the dump, so you can imagine how much the rear was in the air, getting it out of the hole.
Concrete is 32" dia at base & ground level, 15" dia above ground level & 67" tall, to give you some idea.
PS: You will really like the cab.