Changed my mind on cut height after burning up 4 tips on 3/16 plate

For the first two years with my table I ran the torch right down on the sheet because some guy on YouTube swore it gave the cleanest edge. Last month I was cutting a batch of 3/16 brackets for a trailer shop in Boise and went through 4 tips in one afternoon, all blown out and one welded to the plate. A guy on the next bench asked why I was running so low and pulled up the cut chart from the hypertherm manual on his phone, and the book wanted about 1/16 inch above the metal. I set it there and ran the same part again and got a clean square edge with almost no dross on the bottom. The pierce is louder and I had to bump my voltage a touch but my tip life went from about 2 hours to a week and a half. Any of you run a higher cut height than the book says, or is the chart pretty much gospel on your table?