First, let me say the beach is for me too
I asked my doc about Provigil because I was scared to death at the time about taking a stimulent med, aka, Ritalin or Adderall knowing they are widely abused. My doc said, and I should mention, she has 2 ADHD twins, that it is not a good idea. She said Provigil is not for ADHD but for sleep disorders such as narcolepsy. And, that the problem with using Provigil for ADHD is that it oftens makes us irritable and edgy whereas the stimulants promote the calmness so essential for concentration. I must say, I have never used Provigil so take with a grain of salt. If your doc recommends it, it may be worth a try. But my gut feeling is your best course is to make sure your son takes his Adderall on time as prescribed.
To this day the problem I have as an ADHD adult sufferer is the acceptance that I have a brain disorder that isn't going away anytime soon. I don't like the stimulants. But as this point they are the only game in town for anything more than being mildly ADHD. I would like nothing more than for someone to prove me wrong. Let me know if Provigil works for your son.