Chopin Etude in am, Op. 25, No. 11

It begins with a solo theme, that is then echoed in harmony, then the theme returns at forte with a waterfall in the soprano, a veritable barrage of notes showering underneath it. The theme continues to be repeated and developed and sent through various keys, the main melody becoming only a motif at this point, stretching and meandering as it is swallowed by the faster notes, and finally it returns in full force and repeats until it is extended into a terminative, cadential (yet still modulating) section that finally sets us into a heavy PAC. I would say this is a sort of binary form, except I do not know if the return of the A section is in the original key or not, since Chopin's done so much "noodling" around. It certainly seems as though the theme returns in its original key, but that would-be-terminative section seems to modulate out and then cadence in a whole new key to end the piece. But I can't tell. It would be simple and not rounded if it were binary, since the B is really a development section and doesn't go back to repeat the A.