Yea, the caffeine rule is for herbal NBE because most herbs work on making the breasts swell then the swelling becomes growth, and I think the caffeine makes it so it can't swell. Also I think it has to do with water retention, and caffeine stops that. But yea, when I was taking UB I drank coffee, sodas, teas, you name it and still grew, so shouldn't be a problem. While taking herbs I cut out ALL caffeine, this includes coffee, sodas, tea (I would drink all decaf stuff), and (now this one is the kicker and most don't know it) CHOCOLATE!! Chocolate has caffeine in it, so does sport supplements like energy supplements and weight loss supplements. You can't do any of that while taking herbs haha.
The things I would avoid while on BO would be soy. Like soy sauce, tofu, soy milk, etc. Because soy is actually a phyto-estrogen and can counteract with the BO. While taking BO I avoided drinking soy milk, using soy sauce in or on anything, etc. And it sucks because I love Asian food
Other than that with BO just make sure to get your protein in everyday and make sure your temp is normal everyday. That's pretty much it besides making sure to take your pills everyday haha.