This is such an individual thing that it's too hard to place a call on what's considered to be "too much vaping" by person x, y or z. For one thing, you probably don't know what their smoking habit was before they started vaping. I'm not about to even consider passing judgment on what it takes to keep a former 3 PAD unfiltered Camel smoker from relapsing. But I'm pretty sure that their Doctor would be happier with whatever it takes from vaping versus 3 PAD of anything.