i cant say that stock knuckles aren't strong enough for anyone, and i only know of 2 failures, one on my last rig and someone else who posted up recently on pirate i believe. i have heard that stock knuckles have broken on fj80's in austrailia, which is why someone over there came out with a heavy duty knuckle with integrated arms. they're not highsteer, but stronger than stock. my system is both high steer and stronger than stock, and the only reason i made them beefier is, well, why not? a new knuckle had to be made so i made it better. the other advantage is that some people want high steer, but not so high that it limits uptravel. the 3rz 4runner that is running this right now has the tie rod under the arms with a 3link for better uptravel, while my 83 has the tie rod on top of the arms to clear the deaver springs.
so there it is, you might not need anything stronger than stock, but it's available if you decide that you do.