Six thousandths is nothing. Dale's just messing with your head.

That seam warping in Denver is real and I ran into the same mess with a Mandalorian bucket two winters back. What got me was the basement was cold, like 55 degrees, and the Worbla went stiff as a board before I could press it, so I ended up heating it way too long just to get it to move. The outside looked fine but the underside turned into a wrinkly mess and no amount of reheating saved it. EVA on the other hand just shrugs off a cold room, you hit it with the heat gun and it goes soft in seconds. I finally figured out my issue was chasing that smooth hard finish Worbla gives you, which foam only gets after a ton of plasti dip and filler. So maybe you're not bad at shaping it, you might just be fighting the temp in your workspace.