I hate to disagree, but No, normal rules are not applied. I've discussed this not only with electrical engineers, but also with 40 year industrial electricians. There is a reduction for duty cycle limited machines, and a formula that they use that is different than the standard for appliances. And I believe a different requirement for breakers. Again, Section 630 discusses this in detail. If your inspectors didn't know this, then they weren't on top of their game, as it is spelled out in black and white. Run length is considered, of course, but different gauges are allowed according to maximum duty cycle. In my research, I even found a dedicated class offered for wiring welders and similar components.