If you can fabricate it's not extreme. It's quite simple.
And the number of people who lift these anough to need castor correction that decide to return to stock is pretty low.
The only issue I see is
Most people can't weld
Of those that think they can, most shouldn't be welding suspension parts
For those skilled enough, it's a great option. For the rest of us, we take what we can get
A quick search turns up positive reviews
But they only offer 3* of correction it says.
https://forum.ih8mud.com/threads/blackhawk-forged-radius-arms-80-series-caster-correction-for-3-of-lift.1241450/