supports_feature? contains gratuitous punctuation.

A question mark is useful on predicates when they are nouns. For instance type tests. Here is why: widget(x) looks like a constructor: it's making a widget out of x. If we add a question mark: widget?(x) then we know it's a test whether x is a widget. We have other choices there like is_widget(x).

"Supports feature" has a verb and object. The verb is not in imperative form; it's in a statement form. A question mark is not required.