Girdle's theorem is a statement of what can be proven inside some formal system. And science is not about proving things. I've never even worried about worrying about it. Like there's no point in doing physics where you say, well, maybe i won't answer this question because of girdle's procedure. It's not the kind of thing that would potentially worry you. The word practice is doing a lot of work there. But in practice, literally in practice, i have never worried about girdle’s criterion in doing science.