A clause with ὥστε and the infinitive is merely added to the clause containing the main thought in order to explain it. The consequence is stated without any distinction of time and only with difference of stage of action.
a. Since the infinitive expresses merely the abstract verbal idea, its use with ὥστε (as with πρίν) outside of indirect discourse cannot explicitly denote a fact. By its datival nature ( cross1969), the infinitive is simply a complement to, or explanation of, the governing word. ὥστε is one of the means to reinforce this explanatory office of the infinitive. The origin of its use is suggested by the comparison with ὅσος
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].