No other powerups,like more modes(BM mode,sage mode).But his base level skill will improve like learning his second chakra nature(maybe),higher level of taijutsu,speed,and somehow possibly learning fuinjutsu or space time ninjutsu(just a theory).So if these things happen,then his sage mode will also be stronger since Naruto will know more ninjutsu and will have higher taijutsu skill.
But there is one thing for sure ,his BM will improve since he will get more experience in it.Kurama said that their tailed beast transformation is far from perfect,so there is still room for improvement.