You don't "fix" anything, unless by "fix" you mean "turn off broken feature". It's a nice idea, too bad they tout it with such deceptive marketing.
Hm, I hadn't thought it would be misleading and asked for feedback on the heading. I guess the people I asked for feedback already know how it works... Thanks for telling me this because we consider ourselves super straight-shooting and want to be clear. We'll improve.
I believe it works using their Visual Apptimizer, which means that it's only UI changes atm.
As for performance, i've seen no issues.
An example is hiding Facebook login. You can unhide it later (also without resubmitting) when you're ready to put it back.