My tractor can lift more than it can curl

[MossRoad]

By chance is your steering wheel cranked all the way to one side when this occurs?

I read your situation and it reminds me of my machine. The pump feeds the steering valve, and the power-beyond port of the steering valve feeds the loader valves. So, if the steering wheel is cranked all the way to one end, the loader doesn't respond well. I turn the wheel just a shade back in the other direction and the loader operates as normal again.

Don't know if that applies to anyone elses' machines, but that's the way mine is plumbed. Just a thought.

 

[Bavarian]

What I see on a lots of compact tractors is they have an unbelievable dump angle. Sometimes I see tractors parked where the top edge of the bucket almost touches the ground. IMO, all of that travel is not necessary. If you increase the distance where the lower dump linkage attaches to the fork or SSQA frame in relation to the main pin, you would lose some travel, but you would gain curl force since the link is pulling on a longer lever.
I hope it makes sense. All you'd need to do is weld a second set of boltholes on the forks or SSQA frame to change the geometry.