I don’t think the production method has changed, I worked there a decade ago and it seems to be the same, essentially precook the meat and assemble to order. However, I think they no longer pay employees enough to care about speed. They don’t pay more now than when I worked there. In fact, I moved to a state where they pay LESS. Why the hell would anyone working there bust their ass to get food out quickly? You get what you pay for.