Subjunctive (present) with ἄν, when the action lies in the
a. Future, and the verb of the main clause is future indicative or an equivalent form.
b. Present, and the verb of the main clause states a present customary or repeated action or a general truth.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].