I see his point but don't know how much it could effect and how to test it. If the spring was attaching to that lower control arm further back towards the frame I could see what he is saying, the leverage multiplication would make the spring need to be stronger. But being you are out there beyond center and closer to the end I don't see that it would make much of a difference. And how you would measure it, I would simply put it together and see, being I certainly don't have a friggin clue as to the formulas to figure such a thing out.
I see you removed that bar coming forward, looks much better. It really wasn't "triangulating" at all it was going straight out level and doing next to nothing so it wasn't needed. And aesthetically, it is MUCH better without it.
I love this build thanks for posting all the photos.