Literal echelons?

You could use it in an intentionally literal sense, but it would be understood figuratively regardless. Few would consider it in its literal French sense. If you were to italicize it, you could signal that it was meant to be understood as a French word, and then those who speak French would code it that way, but most speakers of English would still think you meant it figuratively and were merely emphasizing the word for idiosyncratic reasons.