An add to cart script to FNL would only be marginally helpful in you increasing your chances at actually obtaining the shoe. The reason being is that even say if you were able to add to cart at exactly when the shoe goes live, you'd be hit by the SPA before you checked out. An add to cart and auto checkout might be a different story however but this again is only looking at a really small time window before the SPA hits. Once you get passed the SPA, you have quite a bit of time to add to cart and checkout. Earlier this year I noticed that the SPA would kick back in a lot faster but as of this summer, the SPA gives you plenty of time to add to cart and checkout before it kicks back in again.
IMHO, FNL is one of the fairest sites out there in getting releases since they
RANDOMLY choose who gets into the site via the SPA. It doesn't matter if you get to the product page at 8:00AM on the dot or 10minutes later. Their site randomly chooses who's next in line to access the site. It results in fun reading on their Facebook page of people complaining about not being able to get in all morning vs. dudes saying "easy cop". LOL And then there are dudes who are pissed because the final checkout button rejects their order since their
billing address is different from their shipping address even though FNL places a temp charge on their card.