At these levels, I detect no impact on taste. That said, I think yolk tastes a little better than pure lecithin. I'm pretty sure I read that optimum lecithin is only .5%. I've been adding more because I have a relatively large bag, and the stuff has a limited life.
The synergy between lecithin and VWG is pretty amazing.
I think what you're describing about gluten and proofing is called proofing tolerance. There's also mixing tolerance. The tolerances go down with bran and up with gluten.
It's annoying adding more ingredients, but they're natural and have a positive impact. Their addition takes a lot less time than all the other parts of the process. I'm willing to do more for whole wheat. Just think of all the people who tried WW and gave up.