Ah, I see, taking "to test A" as an infinitive. But it would be strange to say test B is an alternative without saying what it's an alternative to. The other reading still seems quite unlikely.
The point of STE is to support technical writers who have knowledge of the matter and a style guide. In other words, STE will not make something unambiguous simply by replacing words. The example sentence is just to illustrate a grammar rule: "test" as a verb vs a noun. That is all. You should not assume an STE rule will disambiguate a single sentence pulled out of context.