Yeah, I wouldn't bother paying for it... especially if you're elite. It's hit or miss as to if they'll even call for it, and it's a crapshoot if they'll honor it whether they call for it or not. As an elite, I've gone up when they called for elites only to be told I have to stand in the line in order to board. The lady who boarded in front of me was Zone 3. I didn't care too much since I was in Row 1 and had guaranteed overhead bin space, but would have been royally pissed if I had paid for it and got treated that way. I suspect "Board First" is just another Frontier scam to make a little ancillary revenue and offer little or nothing in return.