A'men to this, Hall seems to be a real werido, BUT his triangle techniques are top shelf stuff. I'm with McCaghren, when i started working hard to get that angle, hooking the leg, leg pressing/curling, its like night and day on the finish %. Its nice to not have to worry where the hell their arm is and that kind of thing. Another thing i saw that helped is a tiny detail from Renzo, where if someone is big or trying to stack & pass, framing your legs to get that angle. I'd have to find the vid, but he's talking about pulling in on your knee, and pushing out on your ankle to both create that perfect angle, and to straight arm "frame" your opponent & keep him from stacking. He creates this frame and then kinda shimmy's his hips back to kill the stack.
Something else i love, and is very high percentage for me is locking the triangle, then getting off my butt and up on both hands, then walking backwards until their base totally collapses and they're on their stomach, easy finish from there, very. And it's not terribly hard to pull off.