Suggestion: Singleton Pattern #6
Description
There are a number of Singleton classes in Core2ez, but they don't follow the Singleton Pattern, designed for the kind of safety a library to be used by non-experts can benefit from:
See: Singleton Pattern or another
While the terms "sloppy" and "naïve" are used to describe the simpler version in the first reference, these are simply synonyms for "single threaded" and are probably completely safe to use in Core2ez; I don't see multi-threading being given special consideration anywhere (in Arduino code in general.)
Using the Pattern is safer (has been industrially tested) and makes the intention of the code clearer.