I have done oatmeal, and its impact was minimal..i'm not a huge fan, so it's hard to make myself eat it when it didn't seem to do much. I can't do beer...I've tried, I just really can't stand beer. Give me wine, and I'm happy
I'm not overly worried about my supply because it pretty much is what she's eating as long as I'm getting in the sessions. I just don't want to risk it depleting to see if I can reduce sessions, kwim? It took a bit to re-regulate after Disney, and it was stressful because I was worrying about it and dipping into freezer stash to cover it. 8x/day sucks, but it also gives me some time where DD isn't attached to me...so in that way it's somewhat relaxing too.
As for the manual...I have used one once or twice, when my Ameda pump broke and I hadn't had the medela in my possession yet. It worked OK - great, even, for the occasional session. For your situation, on the plane, I think I'd be more likely to use the manual.