No, I haven't as yet. I have had to correct TWs with turtles welded, and it was a pain because the #7 port had terrible turbulence from the weld and low pressure area created by it. A piece of aluminum angle welded in the floor is terrible, too. It disrupts the flow pattern, especially #7. I would think that putting dimples in the plenum would be a good place to start if you have hood clearance issues. I plan on using them in both of my personal TWs. Joe-JDC